Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://hea.iki.rssi.ru/kazan2012/TeX/book.pdf Äàòà èçìåíåíèÿ: Wed Aug 29 12:47:40 2012 Äàòà èíäåêñèðîâàíèÿ: Mon Oct 1 22:28:01 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: rosat

Second International Spectrum-RG Conference

Science with eROSITA and ART-XC aboard Spectrum-RG
Kazan, 3-7 September, 2012

Kazan, Russia 2012


pectrum-Roentgen-Gamma (Spectrum-RG) observatory is planned to be launched in 2013 into an L2 orbit. Over the first 4 years, its X-ray telescopes eROSITA and ART-XC wil l survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. It is expected that the survey wil l discover practical ly al l massive clusters of galaxies in the observable Universe and provide a uniquely rich database for studying the large scale structure of the Universe, testing cosmological models and constraining the nature of dark energy. The survey should also discover several mil lions of active galactic nuclei with which it wil l be possible to trace the history of growth of supermassive black holes in evolving galaxies. There also wil l be extensive observations of essential ly al l classes of Galactic X-ray sources, such as active stars, cataclysmic variables and X-ray binaries, as wel l as on hot diffuse interstel lar and intergalactic media.

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Scientific Organizing Committee: Yu. Balega (SAO, Nizhny Arkhyz), I. Bikmaev (KFU), A. Cherepashchuk (MSU, Moscow), E. Churazov (IKI, MPA), T. De Zeeuw (ESO), W. Forman (Harvard, CfA), M. Gilfanov (IKI, MPA), K. Nandra (MPE, Garching), M. Pavlinsky (IKI), P. Predehl (MPE, Garching), N. Sakhibullin (KFU), S. Sazonov (IKI), Deputy chair, R. Sunyaev (IKI), Chair, D. Varshalovich (Ioffe FTI, St. Petersburg), A. Vikhlinin (IKI, CfA) Organizing Committee: Co-chairs I. Gafurov (Rector of the Kazan Federal University) and A. Mazgarov (President of the Academy of Sciences of the Republic of Tatarstan) Deputy chair: N. Sakhibullin (KFU) A. Aganov (KFU), I. Bikmaev (KFU), P. Boldin (IKI), R. Burenin (IKI), M. Bergemann (MPA), M. Gilfanov (IKI), G. Horunzhev (IKI), I. Khabibullin (IKI), R. Krivonos (IKI), A. Krylov (KFU), Yu. Nefedyev (KFU), D. Nurgaliev (KFU), M. Pavlinsky (IKI), M. Revnivtsev (IKI), S. Sazonov (IKI), I. Zhuravleva (MPA)


Abstracts
Monique Arnaud (CEA - Service d'Astrophysique, France) XMM observations of clusters of galaxies and their identification
N/A

Solen Balman (Middle East Technical University) X-ray Observations of Dwarf Novae
Diversity of the X-ray observations of dwarf nova are still not fully understo o d. I will summerize the X-ray spectral characteristics of dwarf novae during the quiescence and outburst. These different behaviour will be discussed in the light of DIM and the characteristics of the perio dic and aperio dic variability in dwarf novae systems. I will also review nature of aperio dic time variability of brightness of dwarf novae. I show that light curves (chosen from XMM-Newton data) of dwarf novae systems in UV and X-ray energy bands demonstrate band limited noise. The frequency of the break indicates inner disk truncation with a range of radii (3 - 10) â 10+9 cm. I show that the RXTE data o d SS Cyg in outburst and quiescence reveal that the inner disk radius moves towards the white dwarf and receeds as the outburst declines to quiescence. Cross-correlations between the simultaneous UV and X-ray light curves find time lags in the X-rays of 96-181 sec consistent with travel time of matter from a truncated inner disc to the white dwarf surface.

Bradford Benson (University of Chicago, USA) The South Pole Telescope: The Sunyaev-Zel'dovich Cluster Survey and Future Plans // The SPT collaboratio
n

The 10-meter South Pole Telescope (SPT) is a millimeter wavelength telescope that recently completed a 2500 sq. deg. survey at 95, 150, and 220 GHz with unprecedented depth and angular resolution. SPT has already led to several ma jor cosmological results, derived from measurements of the fine angular scale primary and


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secondary CMB anisotropies, and the discovery of galaxy clusters via the SunyaevZel'dovich (SZ) effect. I will give an overview of the latest cosmological results from the SPT, including constraints on dark energy, the mass of the neutrinos, the number of relativistic particle species, and the duration of the epo ch of reionization. I will also give an overview of the status and plans to equip the SPT with even more sensitive polarization-sensitive instruments, including the currently operating SPTpol and the future SPT-3G experiments. SPTpol and SPT-3G will continue the current science goals of the SPT, and additionally measure the polarization of the CMB, which will be used to make high signal-to-noise measurements of the gravitational lensing of the CMB by large-scale structure, improve constraints on the mass of the neutrinos, and to search for signatures from Inflation and constrain its energy scale.

Ilfan Bikmaev (Kazan Federal University, Russia) RTT-150 capabilities for optical fol low-up eROSITA and ART-XC targets
// N.Sakhibullin(1), M.Pavlinsky (2), R.Sunyaev (2,3), R.Burenin (2), M.Revnivtsev(2), R. Gumerov Kazan Federal University, Kazan, Russia, 2 - Space Research Institute, Russian Academy of Sciences, Moscow, Russia, 3 - Max-Planck Institute for Astrophysics, Garching, Germany We will report the observational capabilities of the 1.5-meter RussianTurkish telescope (RTT-150) on the optical follow-up of eROSITA and ART-XC targets based on our optical observations of XRay sources detected by INTEGRAL, RXTE, ROSAT, SWIFT.

Dmitry Bisikalo (Institute of Astronomy, RAS, Russia) Accretion disks in close binary stars
We discuss physical pro cesses o ccurring due the mass transfer between the components of close binary stars (CBS). To study the main properties of accretion disks and envelopes in different types of CBS we use results of three-dimensional HD and MHD numerical simulations. Special attention is paid to description of sho ck waves and density waves in the disks. In the frame of the self-consistent description of the MHD flows in CBS we have derived the conditions of the disk formation and found a criterion that splits two types of the flow corresponding to intermediate polars and polars. We have also investigated variations of the main characteristics of the disks depending on the value of the magnetic induction and analyzed the pro cess of the magnetic field generations in the disks. In particular, it has been found that the quasi-perio dic generation of the toroidal magnetic field in the disks leads to the alternation of the accretion and decretion regimes in the inner regions of the disk. The main observational manifestations of the numerically found flow structure elements are also presented.


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Hans Boehringer (Max Planck Institute for Extraterrestrial Physics, Germany) Cosmological Studies with galaxy Clusters
// Gayoung Chon, Luigi Guzzo, Chris Collins On the basis of the ongoing studies with the largest sample of X-ray luminous clusters which has been compiled from the ROSAT All-Sky Survey I illustrate various aspects of characterising the galaxy cluster population in the Universe, in assessing the large scale structure, and in constraining cosmological mo dels. This work provides a comprehensive insight into the ingredients that go into cosmological mo delling of an X-ray galaxy cluster survey. Several important ingredients will be discussed, e.g. the importance of well defined scaling relations of galaxy clusters. Based on this experience I give an outlo ok to the prospects of the eROSITA Survey.

Akos Bogdan (Smithsonian Astrophysical Observatory/CfA, USA) The asynchronous evolution of bulges and supermassive black holes in NGC4342 and NGC4291
// William R. Forman, Irina Zhuravleva, J. Christopher Mihos, Ralph P. Kraft, Paul Harding, Qi Guo, Zhiyuan Li, Eugene Churazov, Alexey Vikhlinin, Paul E. J. Nulsen, Sabine Schindler, Christine Jones According to the theoretical paradigm, supermassive black holes and galaxy bulges are believed to co-evolve, that is they grow in tandem and regulate each others growth. NGC4342 and NGC4291 are relatively nearby early-type galaxies, which host unusually massive black holes relative to their low bulge masses. The black hole-to-bulge mass ratios of NGC4342 and NGC4291 are 6.9% and 1.9%, which significantly exceed the typical observed ratio of 0.2%. Based on Chandra Xray observations, we show the presence of extended dark matter halos around NGC4342 and NGC4291, thereby demonstrating that the observed low bulge masses are not due to tidal stripping, in which dominant fraction of the stellar population has been lost. We thus conclude that the supermassive black holes and the bulges did not co-evolve, as opposed to current theoretical mo dels. The presence of massive dark matter halos around NGC4342 and NGC4291 implies that dark matter halos may play a fundamental role in regulating the black hole growth.


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Marcella Brusa (Max Planck Institute for Extraterrestrial Physics, Germany) The golden epoch of AGN-galaxy co-evolution: prospects for eROSITA
I will present recent results on AGN-galaxy co-evolution of low to mo derate luminous X-ray selected AGN from the CDFS and COSMOS surveys. I will particularly focus on observed AGN (e.g. obscured AGN fraction, space density) and galaxy (e.g. masses, SFR) properties that have been used in the recent years to constrain mo dels of AGN triggering and evolution. I will also discuss the expected contribution of the eROSITA survey towards a better understanding of the co-eval AGN-galaxy growth: for the first time eROSITA will provide a sizable sample (> 1000) of X-ray selected obscured AGN with Lx > 45, still lacking in current X-ray surveys, which represent the ideal laboratories to study the effect of AGN feedback (if any) on the host galaxy properties. Synergies with other multiwavelength surveys which will be available in the eROSITA time frame will also be discussed.

Rodion Burenin (Space Research Institute (IKI), Russia) Optical identifications of galaxy clusters in SRG al l sky survey
The strategies and metho dology of optical identification of galaxy clusters in SRG all sky survey and their further redshift measurements will be considered. The potential of usage of publicly available optical surveys and the amount of additional optical observations will be discussed. The consideration will be based on the similar work made earlier in frames of 400 square degree ROSAT galaxy cluster survey and during the optical identifications of galaxy clusters detected by Plank observatory.

Vadim Burwitz (Max Planck Institute for Extraterrestrial Physics, Germany) eROSITA testing and calibration activities at the MPE Panter X-ray test facility // W. Burkert, H. Bruninger, K. Dennerl, M. Freyberg, P. Friedrich, B. Menz, G. Hartner, MPE, Garching, Germany A description of testing and calibration activities at the MPE facility of the eROSITA mirror mo dules, and the on board source will be presented. Also activities concerning the testing ing system and preparation of the telescope structure parts Panter X-ray of the will be X-ray test calibration CCD co oldescribed.


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Gayoung Chon (Max Planck Institute for Extraterrestrial Physics, Germany) Understanding the large scale structure with the REFLEX II catalogue // Hans Boehringer, Nina Nowak
The ROSAT-ESO Flux Limited X-ray Galaxy Cluster Survey (REFLEX) II catalogue has been completed with a flux-limit of 1.8 â 10-12 erg/s/cm2 in the 0.1-2.4 keV ROSAT band. Larger than its predecessor by a factor of two comprising 918 galaxy clusters it is the largest homogeneous X-ray cluster catalogue existing to day with a well-understo o d selection function. Among the series of the upcoming work to diagnose the large scale structure in the universe we present our effort to compile the first supercluster catalogue based on an X-ray flux-limited sample using a friends-offriends algorithm. We study the statistics of the sample and investigate the effect of environment on the physical properties of the clusters. We discuss the prospects for the eROSITA.

Eugene Churazov (IKI, Russia; MPA, Germany) Galaxy clusters in X-rays: plasma physics, AGN feedback and Cosmology
N/A

Nicolas Clerc (Max Planck Institute for Extraterrestrial Physics, Germany) Cosmological interpretation of large X-ray cluster surveys with CR-HR diagrams
In this talk I will describe the CR-HR metho d jointly taking into account ICM properties and cosmological parameters with minimal assumptions and show how this metho d can be applied to the analysis of large cosmological X-ray surveys. I will then present the results we obtained from a large, serendipitous XMM-Newton cluster survey: X-CLASS, in particular concerning cluster X-ray scaling laws. I will show how this metho d can be applied to the eRosita extragalactic survey and discuss corresponding cosmological forecasts.

Miguel de Avillez (University of Evora, Portugal) The Signature of Non-equilibrium Ionization and


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time-dependent Cooling of the Interstel lar Medium
// Dieter Breitschwerdt The interstellar medium (ISM) is a dynamical system, in which the plasma is naturally driven out of ionization equilibrium due to atomic and dynamic pro cesses, operating on different time scales. We review the effects of the history of the plasma on the co oling function and the asso ciated non-equilibrium X-ray emission, derived from recent 3D high resolution simulations. Our most important results are: (1) in a dynamical ISM, the time-dependent ionization structure and, therefore, the co oling function, varies in space and time, depending on the initial conditions and its history, (2) the co oling paths can be quite different for gas with the same initial temperature, but having different evolution histories, and (3) due to delayed recombination in a dynamic plasma, X-ray emission can o ccur at low temperatures becoming, eventually, stronger than the corresponding emission from a plasma in collisional ionization equilibrium at 106.2 K. This has far reaching consequences for the interpretation of EUV/X-ray spectra, which will be briefly discussed.

Konrad Dennerl (Max Planck Institute for Extraterrestrial Physics, Germany) Comets, charge exchange, and a novel look at the X-ray Universe with eROSITA
The discovery of cometary X-ray emission in 1996 with Rosat has revealed the astrophysical importance of charge exchange (CX) for the generation of X-rays. CX is fundamentally different from other X-ray pro cesses, because the X-rays are not pro duced by hot electrons, but by ions picking up electrons from neutral gas. Comets represent the best natural laboratory for investigating the physics of CX. With its high sensitivity to soft X-rays, its high spectral resolution, and its large field of view, eROSITA will be an ideal satellite for studying the CX interaction of the solar wind with comets and sampling the heavy ion flux at various heliographic latitudes and phases of the solar cycle. The potential of eROSITA for CX studies, however, is not restricted to comets. Also the heliosphere is a source of CX emission. The fact that eROSITA will scan the sky from the L2 region will provide an unprecedented opportunity to map the diffuse X-ray emission from the whole sky, unaffected by emission from the geo corona. By measuring the energy difference between the emission lines from H- and He-like ions, it may become possible to separate CX emission from thermal components of the diffuse soft X-ray emission. The fact that eROSITA will perform eight all-sky surveys will allow to distinguish between temporally variable and persistent features and thus provide an additional, unique opportunity for separating heliospheric emission from other components of the diffuse X-ray emission, in particular from the Lo cal Hot Bubble.


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Serguei Nikolaevitch Dodonov (Special Astrophysical Observatory RAS, Russia) Power of medium band imaging
An observational technique which consists of repeated imaging of a field through a series of medium band (200 - 300 A FWHM) filters are described . Photometry of each image then provides low-resolution spectrophotometry of all detected ob jects. For faint ob jects this metho d comparable in efficiency to slitless spectroscopy, and cover a larger wavelength range. The principal advantages of the metho d are simplicity, accuracy in crowded fields, accurate sky subtraction, and ability to measure many ob jects simultaneously. The photometric measurements from medium band filters provide low resolution spectra for each ob ject which are analysed by a statistical technique for classification and redshift estimation based on spectral template matching. On the base of existing medium band surveys and our observations on 6-m Telescope we discuss the possibility of using medium band observations in optical identification and classification of SRG-ob jects.

Alexis Finoguenov (MPE / University of Helsinki, Germany/ Finland) CODEX: prototype for eROSITA cluster survey
// M.Mirkazemi, E.Rykoff, E.Rozzo, T.Plagge, J.P.Kneib, R.Dupke, J.Henry, L. van Waerbike, J. Carlstrom, P.Spinelli We conduct the CODEX survey to obtain competitive Dark Energy constraints from X-ray clusters. For an unprecedented volume-limited sample of the 294 most massive X-ray selected clusters within the 10,000 sq.degs. BOSS area, we will secure the lowscatter X-ray mass proxies, comprehensive weak lensing calibration, and SZ observations. This survey will be complete to a redshift z < 0.55 for cluster masses above 4.2â 1014 /h Msun. The cosmological promise of this unique sample is high, with a Dark Energy Task Force Figure of Merit (FoM) equal to 160, achieved in combination with BOSS BAO measurements. CODEX is the prototype for eROSITA cluster survey and allows us to prepare the multiwavelength follow-up data, which will be of primary importance for eROSITA cluster science on both parts of the sky. In the talk, the advances in weak lensing, Sunyaev-Zeldovich and spectroscopic studies will be presented.

Marat Gilfanov (IKI, Russia; MPA, Germany) AGN and normal galaxies in the eROSITA al l-sky survey
N/A


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Stefan Gillessen (Max-Planck-Institute for Extraterrestrial Physics, Germany) A gas cloud on its way towards the supermassive black hole at the Galactic Centre
Measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a black hole four million times the mass of the Sun. With the exception of mo dest X-ray and infrared flares Sgr A* is surprisingly faint, suggesting that the accretion rate currently is very low. In 2011 we discovered a dense gas cloud approximately three times the mass of Earth that is falling into the accretion zone of Sgr A*. Our observations fully constrain the clouds orbit. It is highly eccentric with a pericenter distance of only 3100 times the Schwarzschild radius. The pericenter passage will happen in summer 2013 and already now we can see that the cloud has begun to tidally disrupt due to the black holes gravitational force. The cloud also is a probe for the properties of the accretion flow, and ultimately we might have a chance to see how a massive black hole is being fed.

Yuri Nickolaevich Gnedin (Central Astronomical Observatory at Pulkovo of RAS, Russia) Magnetic fields of active galactic nuclei and quasars
// N.A. Silant'ev, S.D. Buliga, M.Yu. Piotrovich, T.M. Natsvlishvili We present estimates of magnetic field in a number of AGNs from the Spectropolarimetric atlas of Smith, Young & Robinson (2002) from the observed degrees of linear polarization and the positional angles of spectral lines (H ) (broad line regions of AGNs) and nearby continuum. The observed degree of polarization is lower than the Milne value in a nonmagnetized atmosphere. We hypothesize that the polarized radiation escapes from optically thick magnetized accretion discs and is weakened by the Faraday rotation effect. The Faraday rotation depolarization effect is able to explain both the value of the polarization and the position angle. We estimate the required magnetic field in the broad line region by using simple asymptotic analytical formulas for Milnes problem in magnetized atmosphere, which take into account the last scattering of radiation before escaping from the accretion disc. The polarization of a broad spectral line escaping from disc is described by the same mechanism. The characteristic features of polarization of a broad line is the minimum of the degree of polarization in the center of the line and continuous rotation of the position angle from one wing to another. These effects can be explained by existence of clouds in the left (keplerian velo city is directed to an observer) and the right (keplerian velo city is directed from an observer) parts of the orbit in a rotating keplerian magnetized accretion disc. Assuming a powerlaw dependence of the magnetic field inside the disc, we obtain the estimate of the magnetic field strength at first stable orbit near the central supermassive black


9 hole (SMBH) for a number of AGNs from the mentioned Spectropolarimetric atlas.

Sergei Grebenev (Space Research Institute (IKI), Russia) Supergiant Fast X-ray Transients - status and prospects for study with Spectrum-RG
I review observational properties and theoretical mo dels of Supergiant fast X-ray transients (SFXTs), a new population of X-ray binaries discovered with INTEGRAL, compare them with the other wind-fed accretors (persistent supergiant binaries and Besystems) and other X-ray transient sources, discuss their lo cation in the Pspin - Porbit diagram emphasizing the importance of measuring both these perio ds for all SFXTs, and finally consider opportunities for their study with Spectrum-RG. In particular, I discuss the importance of measuring their fluxes and spectra in the quiescent state and searching for previously unknown faint sources with similar properties in our and nearby galaxies to prepare a list of candidates in new SFXTs for their further study.

Mikhail Viktorovitch Gubarev (NASA/Marshall Space Flight Center, USA) Development of Mirror Modules for the ART-XC Instrument // B. Ramsey, S.L. ODell, R. Elsner, K. Kilaru, J. McCracken, M. Pavlinsky, A. Tkachenko, I. Lapshov The Marshall Space Flight Center (MSFC) is developing x-ray mirror mo dules for the ART-XC instrument on board the Spectrum-Ro entgen-Gamma Mission under a Reimbursable Agreement between NASA and the Russian Space Research Institute (IKI) ART-XC will consist of seven co-aligned x-ray mirror mo dules with seven corresponding CdTe fo cal plane detectors. Currently, four of the mo dules are being fabricated by the Marshall Space Flight Center (MSFC.) Each MSFC mo dule provides an effective area of 65 cm2 at 8 keV, response out to 30 keV, and an angular resolution of 45 arcsec or better HPD. We will present a status of the ART x-ray mo dule development at MSFC.

Tolga Guver (Sabanci University, Turkey) Modeling the X-ray Spectra of Magnetars
// Ersin Gogus, Feryal Ozel Observed X-ray spectra of strongly magnetized neutron stars reflect the effects of two distinct components at or near the surface of these sources. At the surface, the fully


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ionized highly magnetic Hydrogen atmosphere determines the shape of the continuum spectrum. Furthermore, the interaction of photons with protons in the plasma gives rise to an absorption feature at the proton cyclotron energy that is somewhat weakened by the vacuum polarization resonance. In the magnetosphere these surface photons are further scattered by mildly relativistic charges, causing the observed spectral shape to be further affected. Resulting X-ray spectrum shows significant deviations from a Planck distribution and therefore often fit with a combination of two empirical mo dels like the blackbo dy plus a power-law. We have developed selfconsistent theoretical mo dels that take into account all the relevant physical pro cesses in the surface and in the magnetosphere of magnetars. In this talk I will summarize the properties of this mo del and present the results we have obtained so far from fitting the observed X-ray spectra of magnetars. I will also discuss expected implications of e-ROSITA and ART-XC observations of magnetars to our studies both during the survey phase and with pointed observations. These two detectors will provide a unique data set covering both the very soft and hard end of X-rays simultaneously.

Guenther Gustav Hasinger (Institute for Astronomy, University of Hawaii Manoa, USA) Possibilities for eROSITA cooperation with Hawaii ground-based facilities
As one of the premier astronomy sites in the world, Hawai'i is well positioned to assume a leadership role in the development of the next generation of the world's most powerful ground-based telescopes: the Thirty Meter Telescope (TMT), the Advanced Technology Solar Telescope (ATST), and Pan-STARRS, all slated for the Hawaiian islands. The development of these new facilities represents great scientific potential for the astronomy research community. Pan-STARRS, an innovative wide-field imaging facility developed at IfA, has been operational via its first telescope, PS1, since 2010. With the largest digital camera ever built - 1.4 Gigapixels - and an unprecedented field of 7 deg2 , PS1 generates a time-lapse movie of the Northern sky in 5 pass-bands. PS1 has already discovered a number of potentially hazardous asteroids, comets, and a new class of very luminous supernova explosions. The second telescope, PS-2, is under construction on Haleakala. The TMT, ready for construction on Mauna Kea, will be among the world's most advanced ground-based observatories, operating in wavelengths ranging from the ultraviolet to mid-infrared, integrating the most mo dern innovations in precision control, segmented mirror design, and adaptive optics. It will address bold scientific questions like the search for habitable extrasolar planets, the First Light in the Universe, the earliest Black Holes and the nature of space itself. Combining the excellent sensitivity of the eROSITA survey with the powerful optical, NIR and sub-mm capabilities of the Hawaiian telescopes will allow for fruitful co operations in many different areas of science.


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Gert Huetsi (Max Planck Institute for Astrophysics, Germany) Angular fluctuations in the CXB: Is Fe 6.4 keV line tomography of the large-scale structure feasible?
// Marat Gilfanov Rashid Sunyaev AGN are known to account for a ma jor fraction, if not all, of the Cosmic X-ray background radiation. The dominant sharp spectral feature in their spectra is the 6.4 keV fluorescent line of iron, which may contribute as much as 5 - 10% to the CXB spectral intensity at 2 - 6 keV. Due to cosmological redshift, the line photons detected at the energy E carry information about ob jects lo cated at the redshift z = 6.4/E - 1. In particular, imprinted in their angular fluctuations is the information about the large-scale structure at redshift z. This opens a possibility to perform the Fe K line tomography of the cosmic large-scale structure. The tomographic signal is strongest for ob jects lo cated at the redshift z 1, and at the angular scales corresponding to 100 - 300, therefore an optimal detection can be achieved with an instrument having a rather mo dest angular resolution of 0.1 - 0.5 . For such an instrument, the CCD-type energy resolution of 100 - 200 eV FWHM is entirely sufficient for the optimal separation of the signals originating at different redshifts. Among the currently planned and proposed missions, these requirements are best satisfied by LOFT, despite the fact that it was proposed for entirely different purpose. Among others, clear detection should be achieved by WFXT ( 20 - 35 ) and ATHENA ( 10 - 20 ). eROSITA, in the course of its 4 years all-sky survey, might also lead to a weak detection of the signal.

Dmitry Ivanov (Institute of Applied Astronomy RAS, Russia ) Radio Observations of the Cosmic Gamma-Ray Burst on "Quasar" Network Telescopes
// A.V. Ipatov, D.V. Ivanov, M.A. Kharinov. Institute of Applied Astronomy, Russian Academy of Sciences (St. Petersburg, Russia) "Quasar" network of the Institute of Applied Astronomy consists of three 32-m fully steerable radio telescopes RT-32, lo cated at the Svetlo e, Zelenchukskaya and Badary observatories. Nowadays Quasar is fully operational and regularly participates in the observational programs of IVS, EVN, RadioAstron, etc. From the beginning of 2003 radio telescopes of the "Quasar" network have been used in a single-dish mo de for observing radio emission afterglows of the cosmic gamma-ray bursts (GRB) at Xband. Minimum flux density that can be detected by RT-32 at X-band wavelength is about 6 mJy at 3 level while the weather conditions are fine. As a result there were observed totally 67 GRBs, including asso ciated supernovas (SN). Radio emission was detected from GRB030329, SGR1806-20, GRB080319B and GRB110328A using generally a metho d of drift scanning by elevation. To integrate the signal the scanning of each GRB source was repeated from one to four hours. Observations were carried out within the elevations range from 45 to 70 . Dependence of antenna


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efficiency from elevation was defined observing reference sources 3C295, 3C48, 3C286 and 3147. The daily session was formed in such a manner that between hour-long observations of investigated sources the reference sources observations of ten minutes in duration were placed. Scheduling and pro cessing of observations were made with a special program packages developed in IAA RAS: SchedMaker and ClassVisual.

Vladislav V. Izmodenov (Space Research Institute (IKI), Lomonosov Moscow State University, Russia) Charge transfer reactions at interfaces between neutral gas and plasma: Dynamical effects and X-ray emission
// Elena A. Provornikova Charge-transfer is the main pro cess linking neutrals and charged particles in the interaction regions of neutral (or partly ionized) gas with a plasma. In this paper we illustrate the importance of charge-transfer with respect to the dynamics and the structure of neutral gas-plasma interfaces. We consider the following phenomena: (1) the heliospheric interface - region where the solar wind plasma interacts with the partly-ionized lo cal interstellar medium (LISM) and (2) neutral interstellar clouds embedded in a hot, tenuous plasma such as the million degree gas that fills the socalled "Lo cal Bubble". In (1), we discuss several effects in the outer heliosphere caused by charge exchange of interstellar neutral atoms and plasma protons. In (2) we describe the role of charge exchange in the formation of a transition region between the cloud and the surrounding plasma based on a two-component mo del of the cloud-plasma interaction. In the mo del the cloud consists of relatively cold and dense atomic hydrogen gas, surrounded by hot, low density, fully ionized plasma. We discuss the structure of the cloud-plasma interface and the effect of charge exchange on the lifetime of interstellar clouds. Charge transfer between neutral atoms and minor ions in the plasma pro duces X-ray emission. Assuming standard abundances of minor ions in the hot gas surrounding the cold interstellar cloud, we estimate the X-ray emissivity consecutive to the charge transfer reactions. Our mo del shows that the charge-transfer X-ray emission from the neutral cloud-plasma interface may be comparable to the diffuse thermal X-ray emission from the million degree gas cavity itself.

Ildar Khabibullin (Space Research Institute (IKI), Russia) SRG/eROSITA prospects for detection of GRB afterglows
// S. Yu. Sazonov, R. A. Sunyaev We discuss the potential of the eROSITA telescope on board the Spectrum-X-Gamma observatory to detect gamma-ray burst (GRB) X-ray afterglows during its 4-year allsky survey. The expected rate of afterglows asso ciated with long-duration GRBs


13 without any information on the bursts proper that can be identified by a characteristic power-law light curve in the eROSITA data is 4­8 events per year. An additional small number, 2 per year, of afterglows may be asso ciated with short GRBs, ultra hard (GeV) GRBs and X-ray flashes. eROSITA can thus provide the first unbiased (unaffected by GRB triggering) sample of 40 X-ray afterglows, which can be used for statistical studies of GRB afterglows and for constraining the shape of the GRB log N ­log S distribution at its low-fluence end. The total number of afterglows detected by eROSITA may be yet higher due to orphan afterglows and failed GRBs. The actual detection rate could thus provide interesting constraints on the properties of relativistic jets asso ciated with collapse of massive stars. Finally, eROSITA can provide accurate ( 30 ) co ordinates of newly discovered afterglows within a day after the event, early enough for scheduling further follow-up observations.

Viktor Khartov (Lavochkin Association, Russia) SRG project status and overview
N/A

Dmitry Klochkov (IAAT, Uni. Tuebingen, Germany) Luminosity-related spectral changes as a probe of the accretion regime in accreting pulsars
// A. Santangelo, R. Staubert, P.A. Becker, G. Scho enherr, C. Ferrigno We discuss the dependences of the X-ray spectra of accreting binary pulsars on their luminosity. Our systematic study of the spectrum-luminosity dependences based on the new and archival X-ray data taken with INTEGRAL and RXTE on a sample of bright accreting pulsars indicates the presence of two distinct types of spectral variations with flux. Accreting pulsars with luminosities above 1037 erg/s show a softening of their spectral continuum and a decrease of the cyclotron line energy with flux. In the sources whose luminosity stays below or around 1037 erg/s an opposite behavior is observed. Our analysis shows that the spectrum-luminosity dependence of a particular pulsar is mostly the same on the long time scale (days to years) and on the time scale of individual pulsations (pulse-to-pulse variability). The two types of behavior most probably reflect two different regimes of accretion (i.e. two different configurations of the X-ray emitting accretion column/mound) which are realized in a source depending on whether its X-ray luminosity is above or below a critical value of about 1037 erg/s. The eROSITA instrument onboard SRG will be able to measure the hardness of the powerlaw-continuum in the known and newly discovered transient pulsars while ART-XC will provide an access to the variation of the cyclotron line.


14

CONFERENCE ABSTRACTS

Alexander Kolodzig (Max Planck Institute for Astrophysics, Germany) AGN in the eRosita Al l-Sky survey: Statistics and correlation properties
// M.Gilfanov(1,2), R.Sunyaev(1,2), S.Sazonov(2), G.Huetsi(1) 1 - MaxPlanck Institute for Astrophysics, Garching, Germany 2 Space Research Institute, Russian Academy of Sciences, Moscow, Russia We study statistical properties of active galactic nuclei (AGN) to be detected in the all-sky survey by the eROSITA telescope aboard Spectrum-X Gamma observatory. Assuming that sensitivity of 10-14 erg/s/cm2 (0.5-2 keV band) will be achieved in the course of a 4 years survey, we estimate that 3 million AGN will be detected. The redshift distribution of the detected AGN peaks at z 0.8, with 10% of ob jects lo cated at z > 2. A typical AGN detected in the survey will have the luminosity of 1044 erg/s. The 10% of brightest ob jects will be detected with more than 50 counts and their redshift distribution will peak at z 0.3. We also discuss prospects for studying large scale structure with the survey data.

Roman Krivonos (IKI, Russia; MPA, Germany) X-ray emission from IRAS galaxies
N/A

Andrei Lobanov (Max-Planck-Institut fuer Radioastronomie, Bonn, Germany) Radio - X-ray Connections: Crossing the Turnovers
// J. Anton Zensus (MPIfR, Bonn) The combination of high-sensitivity and high-resolution radio observations with measurements made at higher energies, from the X-ray to the VHE bands in particular, is a powerful to ol to gain deep insight into the lo calisation, classification and physical properties of high-energy emitting ob jects in the Universe. Extended radio campaigns conducted in co-operation with the ROSAT and Fermi-LAT missions present the most striking examples of the success of such co ordinated radio and high-energy observations. The 100-meter radio telescope in Effelsberg has been participating in a number of such co ordinated programs, both as a stand alone instrument and as part of interferometric observations. This fruitful collaboration can now be extended into the next decade, with the anticipated launch of the SpectrumRG mission carrying the eROSITA and the ART-XC instruments on board. The potential for such collaboration can be explored, building upon the past results


15 from ROSAT mission and the ongoing joint programs with the Fermi-LAT mission (Fermi-MOJAVE and FGAMMA programs). A co-ordinated observational program in the radio regime would bring strong benefits to a broad range of observations with eROSITA and ART-XC. The Effelsberg measurements, in particular, will deliver valuable complements to the deep field surveys and studies of high-redshift AGN. The LOFAR MSSS data will provide essential and timely radio counterparts to the all-sky survey (and observations of galaxy clusters in particular). Finally, highresolution interferometry imaging will play a crucial role in lo calisation and characterisation of high-energy emission pro duction sites and transitory phenomena (such as AGN and GRB flares and stellar disruption events near supermassive black holes).

Ilya Lomakin (Lavochkin Association) SRG Project overview
The SC overview of development, // Victor Khartov, Vladimir Babyshkin Status and of the characteristics. the pro ject. main goals

Alexander Anatolievich Lutovinov (Space Research Institute) High-mass X-ray binaries in the Milky Way and LMC. Current view and prospects for SRG
// M.Revnivtsev, S.Tsygankov, R.Krivonos The deep exposure spent by INTEGRAL for observations of different parts of the sky allowed us to obtain flux limited samples of high-mass X-ray binaries in our Galaxy and Large Magellanic Cloud. We have succeeded to obtain luminosity functions of these sources in both galaxies and to compare them in a wide luminosity range. These measurements allowed us to determine the most accurate up to date volume density distribution of sources in the Galaxy and connect it to the history of the star formation. Relations between different subclasses of HMXBs and relate them to different mo des of the wind-fed accretion are discussed. The obtained dependence allowed us to predict a total number of HMXBs in the galaxies and to make predictions for observations of these sources with the eRosita and ART-XC telescopes onboard the SRG mission.

Natalya Lyskova (Max Planck Institute for Astrophysics, Germany; Space Research Institut (IKI), Russia) A simple recipe for estimating masses of el liptical galaxies and clusters of galaxies // E. Churazov


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CONFERENCE ABSTRACTS

We discuss a simple and robust pro cedure to evaluate the total mass/the circular velo city profile of massive elliptical galaxies and clusters of galaxies. The metho d only relies on information about the optical surface density and the pro jected velo city dispersion profiles of tracers and therefore can be applied even in case of po or or noisy observational data. Stars, globular clusters, planetary nebulae or galaxies can be used as mass tracers for ellipticals or galaxy clusters. The proposed pro cedure was tested on a sample of cosmological simulations of individual galaxies and galaxy clusters and then applied to real observational data. Independently the total mass profile was derived from the hydrostatic equilibrium equation for the gaseous atmosphere. Mismatch in mass profiles obtained from optic and X-ray data is used to estimate the non-thermal contribution to the gas pressure and/or to constrain the distribution of tracer's orbits.

Daniel Marrone (University of Arizona, USA) SZ Fol lowup of eROSITA Galaxy Clusters
Confirmation and redshift determination for the enormous catalog of galaxy clusters expected from eROSITA is a daunting challenge, particularly for the highest redshift clusters. Followup observations of these clusters at radio wavelengths via their Sunyaev-Zel'dovich effect signature is a promising to ol for identifying clusters and narrowing the joint uncertainty in the mass-redshift plane. I will discuss the capabilities of current and planned SZ instruments to follow up eROSITA cluster candidates and the various comparisons within the SZ data and between SZ and X-ray that can be used to constrain cluster redshifts.

Dan McCammon (University of Wisconsin, USA) Distribution of hot gas in the Galaxy
// S. L. Snowden Soft X-ray measurements starting in the late 1960s revealed the unexpected presence of large quantities of diffuse million-degree gas in the Galaxy, profoundly changing our understanding of the interstellar medium. The ROSAT all-sky survey in 1990 improved on available data by more than two orders of magnitude in both angular resolution and statistical precision, resulting in a revolution of understanding in many areas and an equal number of new questions. Except for a handful of painfully obtained "postage stamp" observations of the X-ray background with the improved resolution of CCD detectors on mo dern observatories, the ROSAT survey has remained the high-water mark of diffuse background data for over 20 years. The eROSITA survey now promises another order of magnitude improvement in statistics and angular resolution, but the most exciting possibilities are opened by the spectral resolution of the CCD detectors­up to ten times better than the proportional counter resolution of all existing wide area surveys, the promise of the first continuous spectral coverage through the 300-500 eV range, and the great reduction of systematic uncertainties due to the orbit and survey plan.


17

Marat Mingaliev (Special Astrophysical Observatory, Russia) AGNs observations at the RATAN-600 radio telescope
// A. Gorshkov, V. Konnikova As a result of more than 40 years of studies of variability of extragalactic radio sources, it has become clear that the overwhelming ma jority of them with flat spectra are variable on timescales from tens of years to tens of minutes. There is virtually no doubt that long-term variability is a consequence of nonstationary pro cesses in AGN. The most adequate explanation of the observed character of the variability is given by sho ck mo dels. It is most likely that flux variability on daily and intraday timescales has an external cause, and is due scintillation on the turbulent interstellar medium. The main criterion enabling us to cho ose between intrinsic and external origins of IDV, particularly at centimeter wavelengths, is the form of the spectrum. If the spectrum is rising, the cause of the IDV is intrinsic; otherwise, other criteria are required to distinguish between the alternatives. In this report we will present results of a study of the variability of AGNs at the RATAN-600 radio telescope on timescales from several days up to 10 years. Observations were done at six frequencies 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7 GHz. The variability timescales and spectra determined from the analysis of light curves, structure functions, and auto correlation functions are presented. In most cases, the derived variability parameters are sufficient to distinguish intrinsic and external variability. The main argument for a particular type of variability is provided by the form of the spectrum and the frequencies at which this spectrum is formed.

Alexei Moiseev (Special Astrophysical Observatory RAS, Russia) The 6-m telescope BTA: current state and perspectives for SRG survey.
Russian 6-m telescope BTA (Big Telescope Alt-azimuth) operated by Special Astrophysical Observatory OF RUS is the largest optical telescope in Eurasia. We present a short review of the instrumental equipment the telescope, the opportunities for the optical support of Spectrum-RG surveys are also discussed.

Sandor Molnar (Leung Center for Cosmology and Particle Astrophysics, Taiwan) Hard Thermal X-ray Emission from Merging Clusters of Galaxies // Mark Birkinshaw
The next generation of hard X-ray telescopes (Spectr-RG, NuSTAR) will be sensitive to hard X-rays up to 30­80 keV. This hard energy X-ray band is ideal to study merging


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CONFERENCE ABSTRACTS

galaxy clusters because during merging the intra-cluster gas heats up to high temperatures, typically above 20 keV. At these mildly relativistic temperatures the relativistic corrections become important. Therefore we use relativistic thermal bremsstrahlung taking into account electron­ion and electron­electron bremsstrahlung to calculate the spectra and images of merging clusters in the hard X-ray bands. We use merging galaxy clusters from our self consistent FLASH simulations which take dark matter and gas dynamics into account. We estimate the hard band X-ray fluxes for our merging clusters to study the feasibility of their detection with the next generation had X-ray missions.

Tony Mroczkowski (California Institute of Technology/Jet Propulsion Lab, Pasadena, USA) High-Resolution SZE Confirmation of EASS Clusters with MUSTANG-2
// B. Mason, C. Romero, M. Devlin, A. Young, S. Dicker, J. McMahon, E. D. Reese, J. Brevik, J. Sievers, J. Aguirre, M. Rosenman The eROSITA All-Sky Survey (EASS) is expected to lo cate over 105 groups and clusters. However, these detections will be limited to 0.5 resolution and a few tens of photon counts, making spectroscopy and separation of contamination by AGN difficult. MUSTANG-2, the next-generation 9" resolution bolometric instrument for imaging the thermal Sunyaev-Zel'dovich effect (tSZE) from the Green Bank Telescope (GBT), will provide valuable confirmation of EASS candidate clusters, particularly for high redshift ob jects which powerfully leverage cosmological determinations and where X-ray surface brightness is greatly diminished. Lo cated at a latitude of 38 North, the GBT+MUSTANG-2 will be able to observe clusters as low as declination -20 . With up to 349 feed horn-coupled detectors, MUSTANG-2 will be able to measure the integrated tSZE flux densities (i.e. Ysz ) of clusters down to 7 â 1013 M in only a few minutes each, regardless of redshift. These constraints will inform mass estimates of the clusters. Additionally, by combining the eROSITA surface brightness data with deeper MUSTANG-2 observations for a subset of EASS cluster, we can provide a complementary probe of ICM temperature.

Daisuke Nagai (Yale University, USA) Outstanding Chal lenges in the Era of Precision Cluster Cosmology
Recent years have witnessed the emergence of galaxy clusters as powerful laboratories for cosmology and astrophysics. The current generation of cluster surveys have provided independent confirmation of the cosmic acceleration and significantly tighten


19 constraints on the nature of mysterious dark energy and dark matter as well as providing new insights into the growth of massive galaxies and black holes. A number of new surveys (including eROSITA) are underway to advance our understanding of the structure formation and fundamental physics of the cosmos in the coming decade. However, the use of clusters as sensitive cosmological probe requires solid understanding of cluster physics. In this talk, I will discuss several outstanding challenges in our understanding the cluster formation and future prospects for studying the missing cluster physics through the combination of simulation and observational approaches.

Ada Nebot (Observatoire Astronomique de Strasbourg, France) XMM-Newton Survey Science Center Galactic Plane Survey // C. Motch. On behalf of the XMM-SSC
We report on the results from a Galactic survey conducted by the XMM-Newton Survey Science Center. Using optical and infrared follow-up observations supplemented by crosscorrelation with a large range of multiwavelength archival catalogues we identified about one third of the 1000 serendipitously detected X-ray sources at |b| < 20 deg and spread over a wide range of Galactic longitudes. In the soft band, most of the sources are identified with stars, while the hard band is dominated by the extragalactic background population. We show that the surface density of soft sources increases towards the galactic plane, due to a combined effect of X-ray luminosity-age and scale-height-age relations. We have evidence of a Galactic population detected in the hard band. These sources have X-ray and infrared colours consistent with main sequence or evolved binary stars, and their surface density increases towards the Galactic Center (GC). We also identified a few exotic ob jects, such as gammaCas-like stars, T-Tauri stars, HeAe stars, and cataclysmic variables. This Galactic survey combined with similar campaigns covering different Galactic directions (Barcons et al 2002, Della Ceca et al 2004, Motch et al 2010) will help us to classify X-ray sources in an statistical manner. The results of this XMM-Newton Galactic survey provides a useful glance on the huge scientific potential of the eROSITA Galactic survey, in which we expect to observe about 0.3 to 0.5 million stars.

Naomi Ota (Nara Women's University) The ASTRO-H mission
The ASTRO-H mission is the sixth in a series of Japanese X-ray missions, planned to be launched in 2014. ASTRO-H is equipped with a suite of sensitive instruments with a high spectral resolution ( 7 eV) and a very wide energy range from 0.3 to 600 keV. The instruments include the Soft X-ray Spectrometer consisting of the Soft X-ray Telescope and the X-ray micro-calorimeter array (0.3­12 keV); the Hard


20

CONFERENCE ABSTRACTS

X-ray Imager lo cated in the fo cal plane of fo cusing hard X-ray mirrors (5­80 keV); the Soft X-ray Imager as a wide-field X-ray CCD camera for the soft X-ray mirror (0.4­12 keV); a non-imaging Soft Gamma-ray Detector (40­600 keV). The mission aims to understand the dynamics of the evolving Universe and the concentration of energy including non-thermal high-energy phenomena. I plan to present about the mission overview, status, and science themes that will be explored with ASTRO-H's unprecedented spectroscopic capability and wide bandpass.

Mikhail Pavlinsky (Space Research Institute (IKI), Russia) SRG/ART-XC
N/A

Thomas Jeffrey Plagge (University of Chicago/KICP, USA) Measuring the Hubble Constant with Sunyaev-Zel'dovich and X-ray Cluster Data // Massimiliano Bonamente, John Carlstrom, Marshall Joy, Erik Leitch, Adam Mantz, Daniel Marrone, Stephen Muchovej Follow-up measurements of the Sunyaev-Zel'dovich (SZ) effect can be a useful complement to X-ray galaxy cluster surveys. For example, Bonamente et al and others have used the combination of X-ray and SZ data to measure the Hubble constant, finding results consistent with other estimates. The large sample of highredshift clusters to be discovered by eROSITA offers the chance to dramatically increase the precision of this technique, provided SZ follow-up data can be obtained. I will discuss previous H0 results as well as ongoing work using a sample of 100 RASS-selected clusters observed by the Combined Array for Research in Millimeter-wave Astronomy (CARMA). I will also give a preview of the improvements we expect when combining data from eROSITA and an upgraded CARMA array.

Etienne Pointecouteau (IRAP (CNRS/University of Toulouse), France) The pressure profile of galaxy clusters as seen by Planck
// on behalf of the Planck Consortium The pressure support in halos underlies their gravitational potential well. Constraining its distribution is thereby a powerful probe of their matter content (dark and baryonic), and of the physical pro cesses at play within. From the observation of a sample of massive clusters of galaxies in the Planck survey, we have statistically detected their Sunyaev-Zeldovich (SZ) effect out to 3 â R500 , i.e., a density contrast


21 50 - 100. Combining the Planck data with XMM-Newton archive data for our whole sample, we have independently reconstructed the underlying thermal pressure profile from the X-ray and SZ observations. Both are consistent in the region of overlap (i.e., [0.1 - 1] â R500 ). This unique constraint is in fairly go o d agreement with theoretical predictions, and allowed us to provide a precise analytical description making using a GNFW mo del over the whole radial range (i.e., [0.1 - 3] â R500 ). We further derived constraints on the gas mass fraction out to the outskirts of clusters showing an overall compatibility with the expected gas fraction from CMB observations.

Sergei Borisovich Popov (Moscow MV Lomonosov State University, Sternberg Astronomical Institute, Russia) Isolated compact objects for Spectrum-RG
// J. Pons (Univ. Alicante, Spain), P. Boldin (IKI, Moscow), J. Miralles (Univ. Alicante, Spain), B. Posselt (Harvard-Smithsonian CfA, USA), V.F. Suleimanov (Univ. Tubingen, Germany and Kazan University), S.I. Blinnikov (ITEP and SAI, Moscow) We discuss several populations of isolated compact ob jects, which can be potentially observed by Spectrum-RG. The most promising class of ob jects is formed by close-by isolated co oling neutron stars. We apply new co oling curves and discuss properties of these sources on the P-Pdot diagram. We demonstrate that eROSITA can increase the number of known sources of this kind by a factor of 3. New discoveries will be very important to clarify the field decay scenario, and to advance the program for "Grand unification" of neutron stars. Then we discuss isolated co oling young white dwarfs. These ob jects are also promising targets for eROSITA. Many of them have been observed by ROSAT, and eROSITA will increase the number. Finally, we briefly discuss the possibility to observe magnetars using ART-XC and comment on the long-discussed possibility to detect isolated accreting neutron stars.

Konstantin Aleksandrovich Postnov (Moscow MV Lomonosov State University, Sternberg Astronomical Institute, Russia) On the dependence of the cyclotron line energy on the luminosity in accreting X-ray pulsars // N.I. Shakura
The dependence of the cyclotron line energy Ec on the luminosity in accreting X-ray pulsars is revisited and comparison with current X-ray observations is made. It is shown that at luminosities below the lo cal Eddington value L dd the accretion flow E is stopped via Coulomb braking, and a positive correlation of the cyclotron line energy with X-ray flux Ec Lx is expected. Such a correlation is indeed observed in some X-ray pulsars (Her X-1, GX 304, possibly in A0536+26). At X-ray luminosities L dd < Lx < L , where L corresponds to the formation of the optically E


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CONFERENCE ABSTRACTS

thick accretion column, no dependence is expected (Ec const). At higher X-ray luminosities L > L the negative correlation should be observed Ec 1/Lx , as observed in some bright accreting transient X-ray pulsars (4U 0115+63, V 0332+53).

Peter Predehl (Max Planck Institute for Extraterrestrial Physics, Germany) eROSITA - An Overview of Science and Instrument
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the core instrument on the Russian Spektrum-Ro entgen-Gamma (SRG) mission which is current scheduled for launch in 2014. eROSITA will perform a deep survey of the entire X-ray sky. In the soft band (0.5 - 2 keV), it will be about 30 times more sensitive than ROSAT, while in the hard band (2 - 8 keV) it will provide the first ever true imaging survey of the sky. The design driving science is the detection of large samples of galaxy clusters to redshifts z > 1 in order to study the large scale structure in the Universe and test cosmological mo dels including Dark Energy. In addition, eROSITA is expected to yield a sample of a few million AGN, including obscured ob jects, revolutionizing our view of the evolution of supermassive black holes. The survey will also provide new insights into a wide range of astrophysical phenomena, including X-ray binaries, active stars and diffuse emission within the Galaxy.

Roman Rafikov (Princeton University, USA) New Ideas on Mechanisms of Angular Momentum Transport and Variability in Boundary Layers of Accretion Disks // Mikhail Belyaev, James Stone
Disk accretion onto a weakly magnetized central ob ject, e.g. a white dwarf or a neutron star, is inevitably accompanied by the formation of a boundary layer near the surface, in which matter slows down from the highly supersonic orbital velo city of the disk to the rotational velo city of the star. Here I will describe a novel, robust mechanism of the angular momentum transport inside the astrophysical boundary layers. We perform high resolution 2D hydro dynamical simulations in the equatorial plane of a boundary layer and generically find that the supersonic shear in the boundary layer excites non-axisymmetric quasi-stationary acoustic mo des that are trapped between the surface of the star and a Lindblad resonance in the disk. These mo des rotate in a prograde fashion, are stable for hundreds of orbital perio ds, and have a pattern speed that is less than and of order the rotational velo city at the inner edge of the disk. Dissipation of acoustic mo des in weak sho cks provides a universal mechanism for angular momentum and mass transport even in purely hydro dynamic (i.e. non-magnetized) boundary layers. Perio dicity of these trapped mo des may be relevant for explaining the variability seen in accreting compact ob jects.


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Thomas H Reiprich (Bonn University, Germany) Cluster Cosmology with eROSITA
eROSITA will discover about 100,000 galaxy clusters, among them ALL massive clusters in the observable Universe. This go o d statistics together with the tight correlation between X-ray luminosity and gravitational mass makes eROSITA the likely first "Stage IV" dark energy probe. We report on our preparations to using the eROSITA clusters for cosmological constraints. This includes forecasts using the Fisher Matrix and Markov Chain Monte Carlo approaches as well as predictions for which clusters redshifts and mass proxies better than X-ray luminosity can be obtained directly from the eROSITA survey data. These simulations are tailored specifically to eROSITA, taking into account source photons registered at the detectors plus a detailed X-ray and particle background mo del. The employed cosmological tests include the evolution of the cluster mass function and angular clustering. We show that eROSITA will yield competitive constraints on several cosmological parameters.

Mikhail G. Revnivtsev (Space Research Institute (IKI), Russia) Populations of Galactic X-ray sources visible to SRG
In this talk I would like to review the population of Galactic X-ray sources, visible to SRG survey telescopes. Statistics of populations of different sources will provide to ols to probe different physical mechanisms, operational in stellar binaries. Soft and Hard X-ray energy bands, planned to be available on SRG, will be extremely effective for selection of accreting and coronally active sources. It will be extremely important to develop metho ds to combine X-ray and optical/IR data to identify the nature of huge number of sources in the SRG survey. Among other topics of my talks I will try to outline some metho ds to search for populations of stellar binaries with accreting neutron stars and white dwarfs.

Jan Robrade (Hamburger Sternwarte, Germany) Stars in the eROSITA al l-sky survey
The largest fraction of the galactic X-ray sources that will be detected with eROSITA are stars. The stellar content of the eROSITA all-sky survey will however be extremely diverse, with ob jects ranging from nearby magnetically active low-mass stars over young stellar populations to distant massive stars that generate bright X-ray emission from powerful wind sho cks. I will highlight scientific opportunities that will become possible with the eROSITA data of an unprecedented sample of X-ray data from various stellar populations at different ages. eROSITA allows a virtually complete census of the X-ray properties of all stars in the solar neighborho o d out to 25 pc, numerous young T Tauri


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CONFERENCE ABSTRACTS

and HAeBe stars as well as massive OB stars will be detected in star forming regions at all evolutionary stages and the all-sky coverage enables the study of spatially extended regions like stellar asso ciation, moving groups and open clusters. The large number of X-ray detections of rare ob jects like peculiar and evolved stars or substellar ob jects complements the complete stellar samples, allowing to study fundamental X-ray properties of various types of stellar sources. Others astrophysical questions include (pseudo-)diffuse emission, effects of high-energy radiation on disk chemistry and evolution, lo cal star formation history and star formation mo des or the structure of the nearby galactic environment.

Mara Salvato (Max Planck Institute for Extraterrestrial Physics, Germany) Redshifts and added values for AGN eROSITA sources
eROSITA will provide a new Xray map of the distribution of AGN in the sky. In order to exploit its potential for AGN evolution , we need to gather redshifts and know properties of the hosts such as masses and SFR. Not all this information will be provided by spectroscopy, eventually available for at least the brightest sources. I will present what we have learned on photoz and added values for AGN using COSMOS, CDFS and EGS surveys and how it apply to the eROSITA AGN survey.

Sergey Sazonov (Space Research Institute (IKI), Russia) A ful l AGN census by X-ray and infrared al l-sky surveys (SRG vs. WISE)
N/A

Juergen H.M.M. Schmitt (Hamburger Sternwarte, Germany) The high-energy environment of exoplanet host stars
More than 700 hundred stars are now known to be orbited by their own planets. Almost all of these exoplanet host stars are of late type and show the typical signatures of magnetic activity. While the magnetic activity of the Sun is quite low in comparison to its stellar siblings, other planet host stars show a considerable amount of activity and hence crate a high-energy environment very different from the solar system. I will present a systematic discussion of the X-ray properties of exoplanet hosts, single out the most extreme cases and explore the consequences of X-ray and EUV irradiation of planets by their hosts. Furthermore I will address the issue of possible star-planet interactions and discuss the observational evidence for this phenomenon.


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Nikolai Ivanovich Shakura (Moscow MV Lomonosov State University, Sternberg Astronomical Institute, Russia) Microlensing evidence for super-Eddington disk accretion in quasars // P. Abolmasov
Microlensing by the stellar population of lensing galaxies provides an important opportunity to spatially resolve the accretion disks in strongly lense