... A universal physical relation for quasars . ... Harvey Tananbaum and his collaborators have first observed a relation between the soft X-ray and the optical/ultraviolet emission in AGN in 1979. Such relation is nonlinear, and it is usually parameterized as dependence between the logarithm of the monochromatic luminosities at 2500 †Е ( L 2500†Е ) and 2 keV ( L 2keV ) . ... Yet, the dispersion along the L 2500†Е тАУ L 2keV relationship is found to be rather high, typically ~0.35тАУ0.4 in log units. ...

... Scaling relations of galaxies: . ... 2007) . ... This research is now being extended to other clusters such as Hydra and Centaurus, by Ingo Misgeld . ... 2007 , Misgeld et al. 2008 and 2009 ) support a picture where the scaling relations of dwarf galaxies are shaped more by internal than external agents, given that colour-magnitude and magnitude-surface brightness relations agree quite well between the low-density Local Group environment and dense clusters like Fornax and Hydra. Misgeld et al. ...

Large-scale neutral hydrogen distribution and mean velocity field of the Circinus galaxy taken with various arrays of the ATCA. Jones, K.L., Koribalski, B.S. , Elmouttie, M., Haynes R.F. 1999, MNRAS 302, 649 . ... Gas and star formation in the Circinus galaxy . ... The large-scale atomic and molecular gas in the Circinus Galaxy . ... DSS optical image of the Circinus galaxy . ... Left: ESO composite image of the rings and outflow cone of ionized gas in the Circinus galaxy as observed by . ...

PEGASE: Project de'Etude des Galaxies par Synthese Evolutive (by Damien Le Borgne and Brigitte Rocca-Volmerange) . Galaxy colours (by Robin Stevens) . ... Images of radio galaxies and quasars mapped at VLA . Atlas of radio galaxies in 3CRR sample (images, description, classification, etc.) Radio Galaxy and Quasar Images at Other Sites by A.Bridle . ... Radio galaxies in Abell clusters . ... Digitized Sky Survey images . Faint Images of Radio Survey at Twenty-cm at VLA . ...

International Service of Geomagnetic Indices (ISGI) of the IAGA . ... World Data Center C1 for Geomagnetism (WDC-C1), . Solar-Terrestrial Physics Division in Copenhagen, Denmark . ... Sodankyl Geophysical Observatory Geomagnetic and Ionospheric Data . Space Physics Text Book (Oulu): Magnetic activity indices . ... Solar Data Analysis Center (SDAC) . ... Mauna Loa Solar Observatory Analysis Center of HAO/NCAR in Boulder, Colorado . ... Neutron Monitor Server , University of Chicago . ...

... Here comes the SKA. ... HI Gas and Star Formation neutral atomic hydrogen gas cloud (HI) molecular gas cloud (H2) star formation Redshift, Observing the Past The Expanding Universe Hubble`s Law redshift velocity related to distance ... (due to light travel time) Hubble`s Law redshift velocity related to distance distance related to age (due to light travel time) Atmospheric Transmission optical gamma rays, X-rays ultravio let infrared radio ...

... VLA observations and Tully-Fisher distances of gas-poor spiral galaxies in the Virgo Cluster Region . ... The HI-H2 Pressure Relation In Early-Type Galaxies . ... Tracing evolution of early-type spirals through the neutral hydrogen window . ... An Arecibo HI 21-cm Absorption Survey of Rich Abell Clusters . ... The Arecibo Ultra-Deep Survey . ... Absorption in varying galactic environments seen in HI surveys . ... Early-type galaxies with neutral hydrogen in the Virgo cluster from the ALFALFA survey ...

... We have studied scaling relations (virial mass versus CO luminosity, luminosity versus size, linewidth versus size) for molecular clouds in the 30 Dor and N 159 regions in the Large Magellanic Cloud. ... The study of molecular clouds in the Galaxy has resulted in a number of scaling relations between global cloud properties such as mass, density, luminosity, size and velocity dispersion (e.g. Larson (1981) , Scoville & Sanders (1987) , Solomon et al. ... Elmegreen B.G., 1989, ApJ , 338 , 178. ...

... Mindful of these biases, I can now explore the relations between the measured rotation periods and various other observables. The hypothesis behind monitoring stellar variability is that active stars have asymmetric spot distributions on their photospheres. ... They found that only stars with rotation periods greater than seven days show variations greater than 0.4 magnitudes at I. Bouvier et al . ... 1993a) demonstrated a relation between X--ray flux and spectral type in ZAMS stars. ...

Links on this page are to sites that hold information on the Sun , our nearest star . ... Big Bear Solar Observatory (BBSO) , California, USA. Mauna Loa Solar Observatory (MLSO) , Hawai'i, USA. ... Space Environment Center, Current Solar Images , Boulder, Colorado, USA. ... Solar Data Analysis Center, Latest Images , at GSFC, Maryland. ... NSSDC - National Space Science Data Center, Solar Physics (at GSFC). ... NSSDC - National Space Science Data Center, Space Physics (at GSFC). Back to Links ...

... Comets and Asteroids . ... Space Flight . ... By admin October 14, 2010 Posted in: Comets and Asteroids . ... No one on Earth noticed this cataclysm until January 2010, almost a year later, when the LINEAR survey discovered something odd , initially thought to be a comet. ... For details of observations at this time, see Crash of the Asteroids by Sinead McNicholl in the March 2010 issue of Astronotes . Colliding asteroid P/2010 A2 as seen by Rosetta (Image credit: ESA) . ...

... 4. (a) Distribution of distance from the Galactic plane, (b) kinematic diagram, and (c) relation between metallicity and distance from the Galactic plane for RR Lyrae stars with [Fe /H ] > -0.95 . ... The solid line in the middle panel is a regression line, whose slope is determined by the subsystem’s rotation rate; the open circles and dashed line correspond to stars with [Fe/H] > -0.4, and the filled circles and dashed line to stars with -0.95 < [Fe/H] < -0.4. ... next figure | privious figure . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Click for more . ... Binary Star KL Dra . ... Pleasant March: slightly drier, milder and sunnier than average . 2016 April 7th . Cool, damp February with average sunshine; wettest winter for 139 years . 2016 March 16th . Discovering the stars at Armagh: Free St Patrick s day events hosted by Armagh Observatory . 2016 March 15th . ... Mild, wet January, slightly duller than average . ... 2016 January 15th . ...

... The (very) slow rotation of magnetic Ap stars. ... Magnetic stars in young clusters and associations. ... Magnetic fields in low-mass stars from high-resolution infrared spectroscopy. ... Magnetic field measurements of late B-type starss. ... Measurement of magnetic field of FK Com. ... Magnetic field of white dwarfs. ... The magnetic star evolution project (teleconference). ... Conference-2014 . Program . ... Laboratory for the Stellar Magnetism Study of SAO of RAS . ...

... Bad Astronomy . ... Mad Science . ... Site Info . ... Public Talks . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Who is this guy who calls himself "The Bad Astronomer?" ... First, yes, I am a real live astronomer (when people ask me what astronomers do, I tell them "They astronom !" ... These are emitted by powerful objects like black holes, exploding stars, and super-dense neutrons stars. ... Finally, am I really a bad astronomer? ... 2008 Phil Plait. ...

... SUN MOON MERCURY VENUS MARS, JUPITER SATURN . ... Mars . ... Previously understood that magnetic fields were directly related to rotation, so when I read that Mars, like Venus, didn't have one, my understanding crumbled. What exactly causes magnetic fields in planets? ... RELATED TOPICS: MAGNETIC FIELD . Planetary magnetic fields are definitely related to rotation, but directly not so much. ... Get instant access to subscriber content on Astronomy.com! ...

... Discovery of 47-s pulsations in the X-ray source 1RXS J225352.8+624354 / arXiv:1305.3439 , May 2013 . ... Optical spectroscopy of X-ray source IGR J22534+6243 / Atel # 4248 . ... Search for counterparts of newly discovered INTEGRAL/IBIS sources / Atel # 4166 . New INTEGRAL Galactic Plane Survey in SkyView / blog . Likely X-ray counterparts of newly discovered INTEGRAL/IBIS sources / Atel # 4165 . AGN in the INTEGRAL/IBIS 9-year Galactic hard X-ray survey / Atel # 4151 . ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

... 2013: . Evidence for the connection between turbulent gas motions and star formation in dwarf galaxies . ... Moiseev A.V. "Ionized gas rotation curves in nearby dwarf galaxies", Astrophysical Bulletin, 2014, Volume 69, Issue 1 . Moiseev A.V., Tikhonov A.V., Klypin A.A. "What controls the ionized gas turbulent motions in dwarf galaxies", submitted to MNRAS . ... Determination of the mass of a supermassive black hole in AGN Mkn6 based on spectro-polarimetric observations . ... Archive . ...

... Residual , Annual(m) = A0 + (Ais sin m + Aic cos m) , = l( 2/12 ; Trend(m) = (0 + c cos(m ­ tr)) L(m) , L(m) ­ d( L( L( - ; QBO(m) = (k01 + kc1 cos(m ­ QBO)) QBOI(m) ; .. ... Calculated decadal average O3 volume mixing ratios [ppbv] at the earth surface for TM3 1990s CLE (upper) and at the for (upper) STOCHEM 1990s CLE (). Fig. 11a. Decadal averaged ozone volume mixing ratio differences [ppbv] comparing the 2020s and 1990s for TM3 CLE (upper) and STOCHEM CLE (). ... 1:5) 180 /3 2003 . ...