Faint active galaxy puzzle
نویسندگان
چکیده
منابع مشابه
Faint galaxy surveys.
Various K band galaxy surveys have now established 2.2-m galaxy counts from K = 10 to K = 23. The K band counts rise slightly faster than a Euclidean slope to K = 17, at which point they turn over; beyond this magnitude, galaxies also become much bluer. Spectroscopic samples are available between K = 10 and 20 and show that the conventional distance laws hold rather precisely out to a redshift ...
متن کاملEvolution of Faint Galaxy Clustering
The UH8K wide field camera of the CFHT was used to image 0.68 deg2 of sky. From these images, ∼20,000 galaxies were detected to completeness magnitudes V < 23.5 and I < 22.5. The angular correlation function of these galaxies is well represented by the parameterization ω(θ) = AW θ−δ . The slope δ ' −0.8 shows no significant variation over the range of magnitude. The amplitude AW decreases with ...
متن کاملFaint Early - Type Galaxy Ngc 4697
We analyze archival ROSAT HRI, ROSAT PSPC, and ASCA data of the X-ray faint early-type galaxy NGC 4697. The joint ROSAT PSPC + ASCA spectrum is fit by a two-component thermal model, a MEKAL model with kTMEKAL = 0.26 +0.04 −0.03 keV with low metallicity and a bremsstrahlung model with kTBREM = 5.2 +3.0 −1.6 keV. A similar model was found to fit the spectra of another faint early-type galaxy (NGC...
متن کاملHubble Deep Fever: A faint galaxy diagnosis
The longstanding faint blue galaxy problem is gradually subsiding as a result of technological advancement, most notably from high-resolution Hubble Space Telescope imaging. In particular two categorical facts have recently been established, these are: 1) The excess faint blue galaxies are of irregular morphologies,
متن کاملA Survey of Faint Galaxy Pairs
A sample of faint, V magnitude selected, galaxy pairs, having physical separations less than approximately 20h kpc, is used to examine the rise in the merger rate with redshift and the statistical relations between close pairs and the field galaxy population. Redshifts have been obtained for 14 galaxies (V ≤ 22.5) that are in close (θ < 6) pairs, along with a comparison sample of 38 field galax...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1989
ISSN: 0028-0836,1476-4687
DOI: 10.1038/341281a0