- ID:
- ivo://CDS.VizieR/J/A+A/567/A76
- Title:
- COSMOS field radio-loud AGN population at z>1
- Short Name:
- J/A+A/567/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We select a sample of radio galaxies at high redshifts (z>1) in the COSMOS field by cross-matching optical and infrared (IR) images with the FIRST radio data. The aim of this study is to explore the high-z radio-loud (RL) active galactic nuclei (AGN) population at much lower luminosities than the classical samples of distant radio sources, which are similar to those of the local population of radio galaxies. Precisely, we extended a previous analysis focused on low-luminosity radio galaxies. The wide multiwavelength coverage provided by the COSMOS survey allows us to derive their spectral energy distributions (SEDs). We model them with our own developed technique 2SPD that includes old and young stellar populations and dust emission. When added to those previously selected, we obtain a sample of 74 RL AGN. The SED modeling returns several important quantities associated with the AGN and host properties. The resulting photometric redshifts range from z~0.7 to 3. The sample mostly includes compact radio sources but also 21 FR IIs sources; the radio power distribution of the sample covers ~10^31.5^-10^34.3^erg/s/Hz, thus straddling the local FR I/FR II break. The inferred range of stellar mass of the hosts is ~10^10^-10^11.5^M_{sun}_. The SEDs are dominated by the contribution from an old stellar population with an age of ~1-3Gyr for most of the sources. However, UV and mid-IR (MIR) excesses are observed for half of the sample. The dust luminosities inferred from the MIR excesses are in the range, L_dust_~10^43^-10^45.5^erg/s, which are associated with temperatures approximately of 350-1200K. Estimates of the UV component yield values of ~10^41.5^-10^45.5^erg/s at 2000{AA}. The UV emission is significantly correlated with both IR and radio luminosities; the former being the stronger link. However, the origin of UV and dust emission, whether it is produced by the AGN of by star formation, is still unclear. Our results show that this RLAGN population at high redshifts displays a wide variety of properties. Low-power radio galaxies, which are associated with UV- and IR-faint hosts are generally similar to red massive galaxies of the local FR Is. At the opposite side of the radio luminosity distribution, large MIR and UV excesses are observed in objects consistent with quasar-like AGN, as also proved by their high dust temperatures, which are more similar to local FR IIs.
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Search Results
- ID:
- ivo://CDS.VizieR/VII/265
- Title:
- COSMOS Morphological Catalog (V1.1)
- Short Name:
- VII/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The zCOSMOS field benefits of high-resolution imaging in the F814W filter from the HST-ACS (Advanced Camera for Survey). We use standard morphology classifiers, optimised for being robust against band-shifting and surface brightness dimming, and a new, objective, and automated method to convert morphological parameters into early, spiral, and irregular types. We use about 10000 galaxies down to I(AB)=22.5mag with a spectroscopic sampling rate of 33% to characterise the environment of galaxies up to z~1 from the 100kpc scales of galaxy groups up to the 100Mpc scales of the cosmic web.
- ID:
- ivo://CDS.VizieR/J/ApJ/690/1236
- Title:
- COSMOS photometric redshift catalog
- Short Name:
- J/ApJ/690/1236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present accurate photometric redshifts (photo-z) in the 2-deg^2^ COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A {chi}^2^ template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], H{beta}, H{alpha}, and Ly{alpha}) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., {Delta}z=zs-zp) indicates a dispersion of {sigma}_{Delta}z/(1+zs)_=0.007 at i^+^_AB_<22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i^+^_AB_<24 and z<1.25, the accuracy is {sigma}_{Delta}z/(1+zs)_=0.012. The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z~2, albeit with a lower accuracy ({sigma}_{Delta}z/(1+zs)_=0.006 at i^+^_AB_~24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z_m_= 0.66 at 22 <i^+^_AB_<22.5 to z_m_=1.06 at 24.5<i^+^_AB_<25. At i ^+^_AB_<26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/8
- Title:
- COSMOS/UltraVISTA Ks-selected catalogs v4.1
- Short Name:
- J/ApJS/206/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog covering 1.62deg^2^ of the COSMOS/UltraVISTA field with point-spread function (PSF) matched photometry in 30 photometric bands. The catalog covers the wavelength range 0.15-24{mu}m including the available GALEX, Subaru, Canada-France-Hawaii Telescope, VISTA, and Spitzer data. Catalog sources have been selected from the DR1 UltraVISTA K_s_ band imaging that reaches a depth of K_s,tot_=23.4 AB (90% completeness). The PSF-matched catalog is generated using position-dependent PSFs ensuring accurate colors across the entire field. Also included is a catalog of photometric redshifts (z_phot_) for all galaxies computed with the EAZY code. Comparison with spectroscopy from the zCOSMOS 10k bright sample shows that up to z~1.5 the z_phot_ are accurate to {Delta}z/(1+z)=0.013, with a catastrophic outlier fraction of only 1.6%. The z_phot_ also show good agreement with the z_phot_ from the NEWFIRM Medium Band Survey out to z~3. A catalog of stellar masses and stellar population parameters for galaxies determined using the FAST spectral energy distribution fitting code is provided for all galaxies. Also included are rest-frame U-V and V-J colors, L_2800_ and L_IR_. The UVJ color-color diagram confirms that the galaxy bi-modality is well-established out to z~2. Star-forming galaxies also obey a star-forming "main sequence" out to z~2.5, and this sequence evolves in a manner consistent with previous measurements. The COSMOS/UltraVISTA K_s_-selected catalog covers a unique parameter space in both depth, area, and multi-wavelength coverage and promises to be a useful tool for studying the growth of the galaxy population out to z~3-4.
745. COSMOS 70um sources
- ID:
- ivo://CDS.VizieR/J/ApJ/709/572
- Title:
- COSMOS 70um sources
- Short Name:
- J/ApJ/709/572
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large robust sample of 1503 reliable and unconfused 70um selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, LIR (8-1000um), by finding the best-fit template from several different template libraries. The long-wavelength 70 and 160um data allow us to obtain a reliable estimate of LIR, accurate to within 0.2 and 0.05dex, respectively. The 70um data point enables a significant improvement over the luminosity estimates possible with only a 24um detection. The full sample spans a wide range in IR luminosity, LIR~10^8^-10^14^L_{sun}_, with a median luminosity of 10^11.4^L_{sun}_. We identify a total of 687 luminous, 303 ultraluminous, and 31 hyperluminous infrared galaxies (LIRGs, ULIRGs, and HyLIRGs) over the redshift range 0.01<z<3.5 with a median redshift of 0.5. Presented here are the full spectral energy distributions (SEDs) for each of the sources compiled from the extensive multiwavelength data set from the ultraviolet (UV) to the far-infrared. A catalog of the general properties of the sample (including the photometry, redshifts, and LIR) is included with this paper.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A71
- Title:
- CO spectra of 55 LIRGs and ULIRGs
- Short Name:
- J/A+A/628/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present IRAM-30m Telescope ^12^CO and ^13^CO observations of a sample of 55 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in the local universe. This sample is a subset of the Great Observatory All-Sky LIRG Survey (GOALS), for which we use ancillary multi-wavelength data to better understand their interstellar medium and star formation properties. Fifty-three (96%) of the galaxies are detected in ^12^CO, and 29 (52%) are also detected in ^13^CO above a 3{sigma} level. The median full width at zero intensity (FWZI) velocity of the CO line emission is 661km/s, and 54% of the galaxies show a multi-peak CO profile. Herschel photometric data is used to construct the far-IR spectral energy distribution of each galaxy, which are fit with a modified blackbody model that allows us to derive dust temperatures and masses, and infrared luminosities. We make the assumption that the gas-to-dust mass ratio of (U)LIRGs is comparable to local spiral galaxies with a similar stellar mass (i.e., gas/dust of mergers is comparable to their progenitors) to derive a CO-to-H_2_ conversion factor of <{alpha}>=1.8^+1.3^_0.8_M_{sun}_/(K.km/s/pc^2^); such a value is comparable to that derived for (U)LIRGs based on dynamical mass arguments. We derive gas depletion times of 400-600Myr for the (U)LIRGs, compared to the 1.3Gyr for local spiral galaxies. Finally, we re-examine the relationship between the ^12^CO/^13^CO ratio and dust temperature, confirming a transition to elevated ratios in warmer systems.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A27
- Title:
- CO spectra of Virgo cluster galaxies
- Short Name:
- J/A+A/590/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ^12^CO(1-0) and ^12^CO(2-1) observations of a sample of 20 star-forming dwarfs selected from the Herschel Virgo Cluster Survey, with oxygen abundances ranging from 12+log(O/H)~8.1 to 8.8. CO emission is observed in ten galaxies and marginally detected in another one. CO fluxes correlate with the FIR 250um emission, and the dwarfs follow the same linear relation that holds for more massive spiral galaxies extended to a wider dynamical range. We compare different methods to estimate H_2_ molecular masses, namely a metallicity-dependent CO-to-H_2_ conversion factor and one dependent on H-band luminosity. The molecular-to-stellar mass ratio remains nearly constant at stellar masses <=10^9^M_{sun}_, contrary to the atomic hydrogen fraction, M_HI_/M*, which increases inversely with M*. The flattening of the M_H2_/M* ratio at low stellar masses does not seem to be related to the effects of the cluster environment because it occurs for both HI-deficient and HI-normal dwarfs. The molecular-to-atomic ratio is more tightly correlated with stellar surface density than metallicity, confirming that the interstellar gas pressure plays a key role in determining the balance between the two gaseous components of the interstellar medium. Virgo dwarfs follow the same linear trend between molecular gas mass and star formation rate as more massive spirals, but gas depletion timescales, tau_dep, are not constant and range between 100Myr and 6Gyr. The interaction with the Virgo cluster environment is removing the atomic gas and dust components of the dwarfs, but the molecular gas appears to be less affected at the current stage of evolution within the cluster. However, the correlation between HI deficiency and the molecular gas depletion time suggests that the lack of gas replenishment from the outer regions of the disc is lowering the star formation activity.
- ID:
- ivo://CDS.VizieR/J/A+AS/115/439
- Title:
- CO survey of galaxies
- Short Name:
- J/A+AS/115/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large survey of galaxies in the J=1-0 CO line, performed during 1985-1988 using the 15-m SEST and the 20-m millimetre wave telescope of Onsala Space Observatory, is presented. The HPBW of the telescopes are 44" and 33" at 115GHz, respectively. The central positions of 168 galaxies were observed and 101 of these were detected in the CO line. More than 20% of these are new detections. Maps of some of the galaxies are also presented.
- ID:
- ivo://CDS.VizieR/J/A+AS/116/193
- Title:
- CO survey of spirals in Coma supercluster
- Short Name:
- J/A+AS/116/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of the ^12^CO(J=1-0) line at 2.6mm of 65 galaxies located in the Coma supercluster region: 33 actually belong to the Coma supercluster while 32 are either foreground or background objects. These data have been obtained using the NRAO 12m telescope at Kitt Peak (United States), and for four galaxies, using the IRAM 30m telescope at Pico Veleta (Spain). Out of these 65 galaxies, 54 had never been observed in the CO(1-0) line; 49 have been detected by us, of which 37 are new detections. We give molecular gas masses deduced from the CO line integrated intensities, and upper limits for the 16 undetected objects, computed with a Galactic conversion factor N(H_2_)=2.3x10^20^I(CO) and H_0_=75km/s/Mpc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/3445
- Title:
- Covering factor of warm dust in quasars
- Short Name:
- J/MNRAS/430/3445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By combining newly obtained infrared photometric data from the All-Sky Data Release of the Wide-field Infrared Survey Explorer with spectroscopic data from the Seventh Data Release of the Sloan Digital Sky Survey, we study the covering factor of warm dust (CFWD) for a large quasar sample, as well as the relations between CFWD and other physical parameters of quasars. We find a strong correlation between the flux ratio in the mid-infrared to near-ultraviolet and the slope of the near-ultraviolet spectra, which is interpreted as a dust extinction effect. After correcting for dust extinction utilizing the above correlation, we examine the relations between CFWD and active galactic nucleus properties: bolometric luminosity (L_bol_), black hole mass (M_BH_) and Eddington ratio (L/L_Edd_). We confirm the anticorrelation between CFWD and L_bol_. Further, we find that CFWD is anticorrelated with M_BH_ but is independent of L/L_Edd_. Radio-loud quasars are found to follow the same correlations as radio-quiet quasars. Monte Carlo simulations show that the anisotropy of the UV-optical continuum of the accretion disc can have a significant effect, but is not likely to dominate the CFWD-L_bol_ correlation.
