- ID:
- ivo://CDS.VizieR/J/ApJ/742/3
- Title:
- Photometric catalogs for ECDF-S and CDF-N
- Short Name:
- J/ApJ/742/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of deep multiwavelength data for z~0.3-3 starburst galaxies selected by their 70um emission in the Extended-Chandra Deep Field-South and Extended Groth Strip. We identify active galactic nuclei (AGNs) in these infrared sources through their X-ray emission and quantify the fraction that host an AGN. Lastly, we investigate the ratio between the supermassive black hole accretion rate (inferred from the AGN X-ray luminosity) and the bulge growth rate of the host galaxy (approximated as the SFR) and find that, for sources with detected AGNs and star formation (and neglecting systems with low star formation rates to which our data are insensitive), this ratio in distant starbursts agrees well with that expected from the local scaling relation assuming the black holes and bulges grew at the same epoch. These results imply that black holes and bulges grow together during periods of vigorous star formation and AGN activity.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/501/461
- Title:
- Photometric masses of early-type lens galaxies
- Short Name:
- J/A+A/501/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The largest spectroscopically selected sample of strong gravitational lens systems presented and analyzed to date is that of the Sloan Lens ACS (SLACS) survey. For the 57 massive early-type lens galaxies in the sample, photometric and spectroscopic measurements are available from the Sloan Digital Sky Survey (SDSS). By using the SDSS multicolor photometry and lens modeling, we study stellar-mass properties and the luminous and dark matter composition of the early-type lens galaxies in the sample.
- ID:
- ivo://CDS.VizieR/J/ApJ/684/1026
- Title:
- Photometric profiles from GOODS data
- Short Name:
- J/ApJ/684/1026
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted the largest systematic search so far for stellar disk truncations in disklike galaxies at intermediate redshift (z<1.1), using the Great Observatories Origins Deep Survey-South (GOODS-S) data from the Hubble Space Telescope ACS. Focusing on type II galaxies (i.e., downbending profiles), we explore whether the position of the break in the rest-frame B-band radial surface brightness profile (a direct estimator of the extent of the disk where most of the massive star formation is taking place) evolves with time. The number of galaxies under analysis (238 of a total of 505) is an order of magnitude larger than in previous studies. For the first time, we probe the evolution of the break radius for a given stellar mass (a parameter well suited to address evolutionary studies). We have explored the distribution of the scale lengths of the disks in the region inside the break and how this parameter relates to the break radius. We also present results of the statistical analysis of profiles of artificial galaxies, to assess the reliability of our results.
- ID:
- ivo://CDS.VizieR/J/ApJS/158/161
- Title:
- Photometric redshift catalog from the RCS
- Short Name:
- J/ApJS/158/161
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Red-Sequence Cluster Survey (RCS, Cat. <J/ApJS/157/1>) provides a large and deep photometric catalog of galaxies in the z' and R_c_ bands for 90{deg}^2^ of sky, and supplemental V and B data have been obtained for 33.6{deg}^2^. We compile a photometric redshift catalog from these four-band data by utilizing the empirical quadratic polynomial photometric redshift fitting technique in combination with CNOC2 and GOODS/HDF-N redshift data. The training set includes 4924 spectral redshifts. The resulting catalog contains more than one million galaxies with photometric redshifts <1.5 and R_c_<24, giving an rms scatter {sigma}({Delta}z)<0.06 within the redshift range 0.2<z<0.5 and {sigma}({Delta}z)<0.11 for galaxies at 0.0<z<1.5.
- ID:
- ivo://CDS.VizieR/J/ApJ/862/12
- Title:
- Photometric Redshift Catalog (SCUSS, SDSS, WISE)
- Short Name:
- J/ApJ/862/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We publish a photometric redshift catalog based on imaging data of the South Galactic Cap u-band Sky Survey, Sloan Digital Sky Survey (SDSS), and Wide-field Infrared Survey Explorer (WISE). A total of 7 photometric bands are used, ranging from near ultraviolet to near infrared. A local linear regression method is adopted to estimate the photometric redshift with a dedicated spectroscopic training set. The photometric redshift catalog contains about 23.1 million galaxies classified by SDSS. Using the training set with redshift up to 0.8 and r-band magnitude down to 22mag, we achieve an average bias of {Delta}z_norm_=0.000228, standard deviation of {sigma}({Delta}z_norm_)=0.019, and 3{sigma} outlier rate of about 4.2%. The bias is less than 0.01 at z<0.6 and goes up to about 0.05 at z~0.8. Compared with SDSS photometric redshifts, our redshift estimations are more accurate and have less bias.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/61
- Title:
- Photometric redshift of AGNs from XMM- and C-COSMOS
- Short Name:
- J/ApJ/742/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library on the bases of the source properties allowed us to reach an accuracy {sigma}_{Delta}z_/(1+z_spec_)~0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2deg^2^ of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by {Delta}z>0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H_AB_=24mag).
- ID:
- ivo://CDS.VizieR/J/ApJ/871/233
- Title:
- Photometric redshifts in the EGOODS-North field
- Short Name:
- J/ApJ/871/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep J- and H-band images in the extended Great Observatories Origins Deep Survey-North field covering an area of 0.22deg^2^. The observations were taken using WIRCam on the 3.6m Canada-France-Hawaii Telescope. Together with the reprocessed Ks-band image, the 5{sigma} limiting AB magnitudes (in 2" diameter apertures) are 24.7, 24.2, and 24.4 AB mag in the J, H, and Ks bands, respectively. We also release a multiband photometry and photometric redshift catalog containing 93598 sources. For non-X-ray sources, we obtained a photometric redshift accuracy {sigma}_NMAD_=0.036 with an outlier fraction {eta}=7.3%. For X-ray sources, which are mainly active galactic nuclei (AGNs), we cross-matched our catalog with the updated 2M-CDFN X-ray catalog from Xue+ (2016, J/ApJS/224/15) and found that 658 out of 683 X-ray sources have counterparts. GALEX UV data are included in the photometric redshift computation for the X-ray sources to give {sigma}_NMAD_=0.040 with {eta}=10.5%. Our approach yields more accurate photometric redshift estimates compared to previous works in this field. In particular, by adopting AGN-galaxy hybrid templates, our approach delivers photometric redshifts for the X-ray counterparts with fewer outliers compared to the 3D-Hubble Space Telescope catalog, which fit these sources with galaxy-only templates.
- ID:
- ivo://CDS.VizieR/J/ApJS/215/27
- Title:
- Photometric redshifts in the Hawaii-HDF-N
- Short Name:
- J/ApJS/215/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive photometric redshifts (z_phot_) for sources in the entire (~0.4deg^2^) Hawaii-Hubble Deep Field-North (H-HDF-N) field with the EAzY code, based on point-spread-function-matched photometry of 15 broad bands from the ultraviolet (U band) to mid-infrared (IRAC 4.5{mu}m). Our catalog consists of a total of 131678 sources. We evaluate the z_phot_ quality by comparing z_phot_with spectroscopic redshifts (z_spec_) when available, and find a value of normalized median absolute deviation {sigma}_NMAD_=0.029 and an outlier fraction of 5.5% (outliers are defined as sources having |z_phot_-z_spec_|/(1+z_spec_)>0.15) for non-X-ray sources. More specifically, we obtain {sigma}_NMAD_=0.024 with 2.7% outliers for sources brighter than R=23mag, {sigma}_NMAD_=0.035 with 7.4% outliers for sources fainter than R=23mag, {sigma}_NMAD_=0.026 with 3.9% outliers for sources having z<1, and {sigma}_NMAD_=0.034 with 9.0% outliers for sources having z>1. Our z_phot_ quality shows an overall improvement over an earlier z_phot_ work that focused only on the central H-HDF-N area. We also classify each object as a star or galaxy through template spectral energy distribution fitting and complementary morphological parameterization, resulting in 4959 stars and 126719 galaxies. Furthermore, we match our catalog with the 2Ms Chandra Deep Field-North main X-ray catalog. For the 462 matched non-stellar X-ray sources (281 having z_spec_), we improve their z_phot_ quality by adding three additional active galactic nucleus templates, achieving {sigma}_NMAD_=0.035 and an outlier fraction of 12.5%.
- ID:
- ivo://CDS.VizieR/J/AJ/157/99
- Title:
- Photometric redshifts of emission-line galaxies
- Short Name:
- J/AJ/157/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Broadband photometric redshifts are routinely obtained for galaxies to estimate their distances. While effective for many uses, the common resolution in z of 0.01-0.02 is too coarse for detailed large-scale structure mapping, particularly in low-density volumes where the galaxy distribution is least understood. To map galaxies in these low-density volumes, and noting that the percentage of galaxies having emission tends to rise as number density decreases, we have designed a filter system to photometrically measure the redshifts of galaxies with emission. The system consists of two "ramp" filters that cover a common wavelength range with transmission curves sloping from blue to red and from red to blue respectively. This causes the intensity of the image through either filter to be a function of the wavelength of the emission line. A third filter with a bandpass to the side is used to measure and remove the continuum. We have obtained a set of such filters that are tuned for isolating H{alpha} in the redshift range of 3000-9000 km/s. Simulated photometry, applied to spectra of 197 emission-line galaxies from the SDSS, shows the accuracy of the method to be between 250 and 620 km/s, depending on line strength. Actual photometry of a sample of 16 active galaxies measured their redshifts with an accuracy of 573 km/s. This is approximately an order of magnitude more accurate than broadband photometric redshifts. We discuss the errors inherent in this method and present ways to modify the filter set to further improve accuracy.
- ID:
- ivo://CDS.VizieR/J/ApJS/187/560
- Title:
- Photometric redshifts of the 2Ms CDF-S
- Short Name:
- J/ApJS/187/560
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present reliable multiwavelength identifications and high-quality photometric redshifts for the 462 X-ray sources in the ~2Ms Chandra Deep Field-South (CDF-S) survey (Cat. J/ApJS/179/19). Source identifications are carried out using deep optical-to-radio multiwavelength catalogs, and are then combined to create lists of primary and secondary counterparts for the X-ray sources. We identified reliable counterparts for 442 (95.7%) of the X-ray sources, with an expected false-match probability of ~6.2%; we also selected four additional likely counterparts. The majority of the other 16 X-ray sources appear to be off-nuclear sources, sources associated with galaxy groups and clusters, high-redshift active galactic nuclei (AGNs), or spurious X-ray sources. A likelihood-ratio method is used for source matching, which effectively reduces the false-match probability at faint magnitudes compared to a simple error-circle matching method. We construct a master photometric catalog for the identified X-ray sources including up to 42 bands of UV-to-infrared data, and then calculate their photometric redshifts (photo-z's). The typical photo-z accuracy is ~6%-7%.
