Discovery of a Dwarf Poststarburst Galaxy near a High Column
... The first systematic attempt to discover galaxies associated with the Ly absorbers toward 3C 273 was conducted by M93, who used deep narrowband and broadband imaging in an attempt to detect faint galaxies that might be associated with Ly clouds. They then performed follow-up multiobject spectrosco ...
... The first systematic attempt to discover galaxies associated with the Ly absorbers toward 3C 273 was conducted by M93, who used deep narrowband and broadband imaging in an attempt to detect faint galaxies that might be associated with Ly clouds. They then performed follow-up multiobject spectrosco ...
Fraction of the X-ray selected AGNs with optical emission lines in
... −1.4 %, suggesting the rising tendency of AGN fraction in clusters with redshift from 0.05 to 1.5. With the Chandra Multiwavelength Project (ChaMP) and SDSS data, using L0.5−8keV > 1042 erg s−1 to select AGNs, Haggard et al. (2010) found that the AGN fraction in groups is 0.16% for z ≤ 0.125, and 3. ...
... −1.4 %, suggesting the rising tendency of AGN fraction in clusters with redshift from 0.05 to 1.5. With the Chandra Multiwavelength Project (ChaMP) and SDSS data, using L0.5−8keV > 1042 erg s−1 to select AGNs, Haggard et al. (2010) found that the AGN fraction in groups is 0.16% for z ≤ 0.125, and 3. ...
AGN host galaxies at redshift z ≈ 0.7: peculiar or not?
... The analysis of the underlying host galaxy in AGN images is a challanging task, particularly in cases of low flux contrasts between the host and nucleus. The key issue for an accurate removal of the central point source and a determination of the host properties is a good knowledge of the Point Spre ...
... The analysis of the underlying host galaxy in AGN images is a challanging task, particularly in cases of low flux contrasts between the host and nucleus. The key issue for an accurate removal of the central point source and a determination of the host properties is a good knowledge of the Point Spre ...
compaq - Sloan Digital Sky Survey
... Local census of the galaxy population: How did galaxies form? Find the most distant objects in the Universe: What are the highest quasar redshifts? ...
... Local census of the galaxy population: How did galaxies form? Find the most distant objects in the Universe: What are the highest quasar redshifts? ...
SPICA Yellow Book
... through the investigation of the cold and obscured parts of the Universe, where the basic processes of formation and evolution occur. Deep exploration of the cold Universe using high spatial resolution observations in the Far Infrared (FIR) and sub-mm started in 2009 with the launch of the Herschel ...
... through the investigation of the cold and obscured parts of the Universe, where the basic processes of formation and evolution occur. Deep exploration of the cold Universe using high spatial resolution observations in the Far Infrared (FIR) and sub-mm started in 2009 with the launch of the Herschel ...
Probing nuclear activity versus star formation at z ∼ 0.8 using near
... formation properties of 58 X-ray-selected AGN at 0.5 < z < 1.4 by modelling their multifrequency SEDs and did not find strong evidence for either highly suppressed or enhanced star formation when compared to a mass-matched sample of galaxies at the same redshift. However, these AGN were selected to ...
... formation properties of 58 X-ray-selected AGN at 0.5 < z < 1.4 by modelling their multifrequency SEDs and did not find strong evidence for either highly suppressed or enhanced star formation when compared to a mass-matched sample of galaxies at the same redshift. However, these AGN were selected to ...
SOME CONSTRAINTS ON GALAXY EVOLUTION IMPOSED BY
... for cD, E and S0 galaxies, compared to < S > = 1.1 for all spirals. The specific frequency < S > = 9.3 in nine cD/E galaxies is higher than that in 34 E + S0 galaxies for which < S > = 5.1. Furthermore, the specific frequency < S > = 0.8 in eight late-type spirals (Sb - Scd) is significantly lower t ...
... for cD, E and S0 galaxies, compared to < S > = 1.1 for all spirals. The specific frequency < S > = 9.3 in nine cD/E galaxies is higher than that in 34 E + S0 galaxies for which < S > = 5.1. Furthermore, the specific frequency < S > = 0.8 in eight late-type spirals (Sb - Scd) is significantly lower t ...
CEA
... Every GRB signals the birth of a sizable stellar-mass black hole somewhere in the observable universe. Long GRBs occur in star forming galaxies at an average redshift of ~1. There are now plausible or certain host galaxies found for all but 1 or 2 GRBs with X-ray, optical or radio afterglows p ...
... Every GRB signals the birth of a sizable stellar-mass black hole somewhere in the observable universe. Long GRBs occur in star forming galaxies at an average redshift of ~1. There are now plausible or certain host galaxies found for all but 1 or 2 GRBs with X-ray, optical or radio afterglows p ...
STELLAR MASSES AND STAR FORMATION RATES OF LENSED DUSTY STAR-FORMING... FROM THE SPT SURVEY
... Note. — We adopt the source redshift for SPT0538-50 obtained with ATCA CO(1-0) spectroscopy by Aravena et al. (2013). The lens parameters derived from GALFIT (e.g., Sérsic index, effective radius) are held fixed during the de-blending process. For the ones with multiple components, we list the Sérs ...
... Note. — We adopt the source redshift for SPT0538-50 obtained with ATCA CO(1-0) spectroscopy by Aravena et al. (2013). The lens parameters derived from GALFIT (e.g., Sérsic index, effective radius) are held fixed during the de-blending process. For the ones with multiple components, we list the Sérs ...
from z=0 to z=1
... ratio (attenuation) for UV galaxies. For IR (24m) selected galaxies at z~0.6, no evidence is found for evolution of either the stellar mass or the IR/UV ratio for given LIR. 8. Both IR and UV evolve significantly from z=0 to z=1, and the ratio IR/UV increases by ~ 4. This is consistent with the ...
... ratio (attenuation) for UV galaxies. For IR (24m) selected galaxies at z~0.6, no evidence is found for evolution of either the stellar mass or the IR/UV ratio for given LIR. 8. Both IR and UV evolve significantly from z=0 to z=1, and the ratio IR/UV increases by ~ 4. This is consistent with the ...
Descending from on high: Lyman-series cascades and spin
... generated by the first generation of collapsed objects. These highredshift objects are highly biased, leading to large variations in their number density. This, combined with the 1/r 2 dependence of the flux, causes large fluctuations in the Lyα background, which can be probed through their effect o ...
... generated by the first generation of collapsed objects. These highredshift objects are highly biased, leading to large variations in their number density. This, combined with the 1/r 2 dependence of the flux, causes large fluctuations in the Lyα background, which can be probed through their effect o ...
Groups of galaxies in the SDSS Data Release 7*
... effects can be observed here. In the majority of recent papers dedicated to group searches, the group finders are tuned with mock N-body catalogues (Eke et al. 2004; Yang et al. 2005). The mock group catalogues are homogeneous and all parameters of the mock groups can be easily found and applied to s ...
... effects can be observed here. In the majority of recent papers dedicated to group searches, the group finders are tuned with mock N-body catalogues (Eke et al. 2004; Yang et al. 2005). The mock group catalogues are homogeneous and all parameters of the mock groups can be easily found and applied to s ...
Radio observations of the 13hXMM–Newton/ROSAT Deep X
... as source 1, in Table A1. It has a linear size of ∼40 arcsec, which is just beyond the limit of extended structure detectable by the VLA in A configuration. It is the brightest source near the field by almost an order of magnitude and its residual sidelobes, after cleaning, were the major noise cont ...
... as source 1, in Table A1. It has a linear size of ∼40 arcsec, which is just beyond the limit of extended structure detectable by the VLA in A configuration. It is the brightest source near the field by almost an order of magnitude and its residual sidelobes, after cleaning, were the major noise cont ...
17 April 2013 When Galaxies Collide Professor Carolin Crawford
... clouds of the Magellanic Stream which may well have formed in situ. Models for the dynamics of the satellites and the Milky Way suggest that the tiny galaxies may be completely disrupted and disintegrate within a few hundred million years. 5.2 The Sagittarius Dwarf Elliptical Galaxy Another satellit ...
... clouds of the Magellanic Stream which may well have formed in situ. Models for the dynamics of the satellites and the Milky Way suggest that the tiny galaxies may be completely disrupted and disintegrate within a few hundred million years. 5.2 The Sagittarius Dwarf Elliptical Galaxy Another satellit ...
Redshift
In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. In general, whether or not the radiation is within the visible spectrum, ""redder"" means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. Another kind of redshift is cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns. Redshifts are also seen in the spectroscopic observations of astronomical objects. Its value is represented by the letter z.A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat. However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity. Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws. There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).