Next: NGC 660 Up: The Group of Nearby Previous: The Group of Nearby . NGC 253 is a nearby edge-on galaxy and the brightest member of the Sculptor group. ... The strong and extended radio emission makes it especially suitable for H I absorption measurements (see e.g., Combes, Gottesman & Weliachew 1977; Dickey, Brinks & Puche 1992; Koribalski, Whiteoak & Houghton 1995). ... Column (1): Galaxy name. ... Next: NGC 660 Up: The Group of Nearby Previous: The Group of Nearby Baerbel Koribalski . ...

We present optical, ultraviolet (UV) and extreme ultraviolet (EUV) results for a new active late-type dwarf star discovered by the Extreme Ultraviolet Explorer (EUVE). A large flare with an energy in excess of 1E35 erg and duration of ~1.1 days was detected in the EUVE Lex/B band (60--200AA). ... The `quiescent' EUV emission of the source is similar to the most active flare stars with the `quiescent' optical spectrum showing strong H alpha, Ca II H Mg II h emission and Li I 6707.8A absorption. ...

High-resolution mid-infrared spectra are presented for 155 nuclear and extranuclear regions from the Spitzer Infrared Nearby Galaxies Survey (SINGS). ... Conversely, the radiation hardness for galaxy nuclei powered by accretion around a massive black hole is independent of metal abundance. ... However, similar to [Ne III] 15.56 ЮМm/[Ne II] 12.81 ЮМm, these mid-infrared line ratios lose their AGN/star-formation diagnostic powers for very low metallicity star-forming systems with hard radiation fields. ...

... Flux density at 1 GHz (/Jy): 8 . ... Optical: Filaments and diffuse emission. ... Distance: Mean optical velocity indicates 6.7 kpc, H I absorption indicates 2.3 kpc. ... NRAO 300-ft at 2.7 GHz (5': S=5.3?0.6 Jy). ADS . van den Bergh 1978, ApJS, 38, 119. Optical. ... 1975, AuJPA, 37, 75. Molonglo at 408 MHz (3': S=11.7 Jy). ... Arecibo S 430 MHz =20?10 Jy, S 318 MHz =20?3.6 Jy. ... Einstein and optical observations. ... VLA at 327 MHz (59") and 1.49 GHz (52"), plus X-rays. ...

... 55 Cancri: Familiar Planet Discovered . ... Is our Solar System unique? The discovery of a Jupiter-like planet in a Jupiter-like orbit around nearby Sun-like star 55 Cancri, announced yesterday, gives a new indication that planetary systems similar to our Solar System likely exist elsewhere. ... Part of the Sun disappeared behind the Moon earlier this week. Previously, the waning Moon was best visible from all places on Earth during the early morning hours because it trailed the Sun. ...

... astro-ph/0003002 We cross-identified the ROSAT Bright Source Catalog (RBSC) and the NRAO VLA Sky Survey (NVSS) to construct the RBSC-NVSS sample of the brightest X-ray sources (~0.1 counts s^{-1} ~= 10^{-12} ergs cm^-2s^-1 in the 0.1--2.4 keV band) that are also radio sources (S ~= 2.5 mJy at 1.4 GHz) in the 7.8 sr of extragalactic sky with |b| > 15deg and DEC > -40deg. ... We used the more accurate radio positions to make reliable X-ray/radio/optical identifications down to the POSS plate limits. ...

... The presence of solid­state emission bands is compared to other indicators of circumstellar material, such as Hff emission, optical variability and sub­mm continuum fluxes. ... However, a strong dependence on spectral type of the central star seems to be present: stars with spectral type earlier than B9 show either amorphous silicate in absorption or infrared spectra dominated by PAH emission, whereas more than 70% of the stars of later spectral type show silicate emission. ...

... Some optical observations of auroral forms have indicated anomalous enhancement of emission within a very limited altitude range of about 2 km (Oguti, 1975; Stenbaek-Nielsen and Hallinan, 1979; Stenbaek-Nielsen, 1980a, b), and have been called as enhanced aurora. ... Res. ... Oguti, T., Two-tiered auroral band, J. Atmos. ... Res., 85 , 4299, 1980b. Stenbaek-Nielsen, H. C., and T. N. Hallinan, Pulsating auroras: Evidence for noncollisional thermalization of precipitating electrons, J. Geophys. ...

... 2004 September 1 . An Inner Neptune for 55 Cancri . ... The discovery of a Neptune -mass planet in an sub-Mercury orbit around nearby Sun -like star 55 Cancri , announced yesterday along with the discovery of other similar systems, gives a new indication that planetary systems as complex as our own Solar System likely exist elsewhere. ... The above drawing depicts what this planet might look like, assuming a mass similar to Neptune , but a composition similar to Earth. ... About APOD | ...

... The Butcher-Oemler Effect Blue Fraction, fB Redshift , z The Butcher-Oemler Effect Blue Fraction, fB Abell 370 Redshift , z Abell 370 a galaxy cluster at z = 0.37 Abell 370 , a galaxy cluster at z = 0.37 large galaxy cluster of order same size as Coma similar cluster velocity dispersion and X-ray gas temperature GMRT ~34 hours on OII] Star Formation Rate Average all 168 [OII] emission galaxies line from Bell 2003 Radio Continuum vs. ...

... Dust in the region is studied photometrically at ultraviolet, optical, and far-infrared wavelengths to analyze nebular colors, grain properties, and scattering geometry. Constraints on this geometry are provided by spectroscopy of radio emission lines and optical absorption lines of the interstellar gas, which also reveal a significant amount of fine-scale filamentary structure. ... Return to Thesis Page ...

Astronotes Armagh Planetarium's Stellar Blog! ... Our Galaxy . Milky Way . Stars . ... Other Galaxies . ... Barred spiral galaxy NGC 6744 is located in a constellation of the southern hemisphereтАЩs sky, called Pavo (Latin for peacock). At a distance from our Solar System of about 30 million light years, NGC 6744 is not only one of the closest spiral galaxies but is thought to be one of the visible galaxies most like our own Milky Way. Is it our cosmic doppelganger? ...

Emission Line -- Continuum Correlations in Low­Redshift Quasars Belinda Wilkes , Smita Mathur, Jonathan McDowell (SAO) and Ari Laor (Caltech) We investigate the relation between the observed optical emission line strengths, widths and ratios and the observed continuum properties for two samples of quasars: 43 Einstein observed quasars for which we have obtained IR--soft­X­ 1994). ... 1) Contrary to PG sample and Shastri et al. ...

... Discussions about options for introducing polarizing optics to the high resolution spectrometer NES, recently developed at the 6m telescope by V.Panchuk, have also been held. ... A strong double-peaked emission in the H-alpha line was found in 1985 and explained in terms of a rotating equatorial disk model, first proposed by Jones et al. (1993) for this object. ... Based on high resolution optical spectra we obtained in 1995, the effective temperature Teff=8500K has been estimated for IRC+10420. ...

... Staff . ... Galaxies, AGN, Cosmology . ... Star formation . ... ALMA . ... A local window on galaxy formation with ALMA . ... Highly star-forming, metal-poor dwarf galaxies in the vicinity of the Milky Way offer an unique window over the conditions of primordial galaxy formation and evolution. ... The primary science goals of submillimeter astronomy with ALMA are: the high-redshift Universe and Cosmology, galaxies and AGNs, star formation and interstellar medium, exoplanets and stellar evolution. ...

We report here on those proposed UIT targets that, in fact, were successfully acquired. ... Note on Filters: . A1 centered at 2500 angstroms with a width of 1200 angstroms . ... Sextans A is a low mass dwarf companion to the Milky Way Galaxy. It is sufficiently close that it is easily resolved into its individual stars. ... An exposure of 1100 seconds through the A1 and B1 filters was obtained. NGC 2903 Is a relatively nearby mostly face-on galaxy with active star formation. ...

... OXIDIZED AND HYDRATED SILICATES ON M- AND S- ASTEROIDS: SPECTRAL INDICATIONS. ... In particular, it was shown that a considerable fraction (ab. 35%) of the mainbelt M-type asteroids have absorption bands at 3 µm [3, 6] diagnostic of water of hydration. At the same time it was found that the visible-range reflectance spectra of some M- and Sasteroids include absorption features characterizing presence of oxidized silicates [4, 5]. ... The reflectance spectra of 161 Athor (Fig. 1), 497 Iva (Fig. ...

. The dwarf galaxy Henize 2-10, seen in visible light by the Hubble Space Telescope. The central light-pink region shows an area of radio emission seen with the Very Large Array. This area indicates the presence of a supermassive black hole drawing in material from its surroundings. This also is indicated by strong X-ray emission from this region detected by the Chandra X-Ray Observatory. Reines, et al., David Nidever, NRAO/AUI/NSF/NASA

... Keck spectropolarimetry, giving spectral coverage from Ly- to beyond CIII], and HST imaging of a sample of powerful radio galaxies with has been obtained. ... This is a short progress report on a rather extensive programme we are carrying out to study the structure and composition of high redshift radio galaxies (HzRG) -- and, by implication, the host galaxies of radio quasars -- using observations in the optical, IR and mm bands. ... An example of the NICMOS and WFPC 2 imaging is shown in Figure 2 ...

... Facts and artifacts in interstellar diamond spectra. ... Optical constants: . nanodiamonds Some details: . The nanodiamonds were extracted from Murchison meteorite material using the procedures similar to those employed by Tang and Anders (1988, Geochim. ... Acta, 52, 1235). The mass absorption coefficient in the range from 0.2 to 500 micron was derived from the transmission spectra of the diamonds in KBr and polyethylene pellets for T = 10 and 300 K. Back to carbonaceous species page . ...