- ID:
- ivo://CDS.VizieR/J/ApJ/829/44
- Title:
- NGVS. XX. RedGOLD background galaxy clusters
- Short Name:
- J/ApJ/829/44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We build a background cluster candidate catalog from the Next Generation Virgo Cluster Survey (NGVS) using our detection algorithm RedGOLD. The NGVS covers 104deg^2^ of the Virgo cluster in the u^*^,g,r,i,z-bandpasses to a depth of g~25.7mag (5{sigma}). Part of the survey was not covered or has shallow observations in the r band. We build two cluster catalogs: one using all bandpasses, for the fields with deep r-band observations (~20deg^2^), and the other using four bandpasses (u^*^,g,i,z) for the entire NGVS area. Based on our previous Canada-France-Hawaii Telescope Legacy Survey W1 studies, we estimate that both of our catalogs are ~100% (~70%) complete and ~80% pure, at z<=0.6 (z<~1), for galaxy clusters with masses of M>~10^14^M_{sun}_. We show that when using four bandpasses, though the photometric redshift accuracy is lower, RedGOLD detects massive galaxy clusters up to z~1 with completeness and purity similar to the five-band case. This is achieved when taking into account the bias in the richness estimation, which is ~40% lower at 0.5<=z<0.6 and ~20% higher at 0.6<z<0.8, with respect to the five-band case. RedGOLD recovers all the X-ray clusters in the area with mass M_500_>1.4x10^14^M_{sun}_ and 0.08<z<0.5. Because of our different cluster richness limits and the NGVS depth, our catalogs reach lower masses than the published redMaPPer cluster catalog over the area, and we recover ~90%-100% of its detections.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/546/694
- Title:
- NICMOS star formation history
- Short Name:
- J/ApJ/546/694
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an extensive analysis of the star formation rates determined from the NICMOS deep images of the northern Hubble Deep Field. We use SED template fitting photometric techniques to determine both the redshift and the extinction for each galaxy in our field. Measurement of the individual extinctions provides a correction for star formation hidden by dust obscuration. We determine star formation rates for each galaxy based on the 1500{AA} UV flux and add the rates in redshift bins of width 1.0 centered on integer redshift values.
- ID:
- ivo://CDS.VizieR/J/ApJ/827/74
- Title:
- [NII]/H{alpha} ratio in galaxies with KMOS^3D^
- Short Name:
- J/ApJ/827/74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of the [NII]/H{alpha} ratio as a probe of gas-phase oxygen abundance for a sample of 419 star-forming galaxies at z=0.6-2.7 from the KMOS^3D^ near-IR multi-integral field unit (IFU) survey. The mass-metallicity relation (MZR) is determined consistently with the same sample selection, metallicity tracer, and methodology over the wide redshift range probed by the survey. We find good agreement with long-slit surveys in the literature, except for the low-mass slope of the relation at z~2.3, where this sample is less biased than previous samples based on optical spectroscopic redshifts. In this regime we measure a steeper slope than some literature results. Excluding the contribution from active galactic nuclei from the MZR reduces sensitivity at the high-mass end, but produces otherwise consistent results. There is no significant dependence of the [NII]/H{alpha} ratio on star formation rate at fixed redshift and stellar mass. The IFU data allow spatially resolved measurements of [NII]/H{alpha}, from which we can infer abundance gradients for 180 galaxies, thus tripling the current sample in the literature. The observed gradients are on average flat, with only 15 gradients statistically offset from zero at >3{sigma}. We have modeled the effect of beam smearing, assuming a smooth intrinsic radial gradient and known seeing, inclination, and effective radius for each galaxy. Our seeing-limited observations can recover up to 70% of the intrinsic gradient for the largest, face-on disks, but only 30% for the smaller, more inclined galaxies. We do not find significant trends between observed or corrected gradients and any stellar population, dynamical, or structural galaxy parameters, mostly in agreement with existing studies with much smaller sample sizes. In cosmological simulations, strong feedback is generally required to produce flat gradients at high redshift.
- ID:
- ivo://CDS.VizieR/J/ApJ/610/128
- Title:
- NIR colors of hard X-ray-selected AGN
- Short Name:
- J/ApJ/610/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of near-infrared photometry (J, H, K_s_) for a hard X-ray-selected sample of active galactic nuclei (AGNs) obtained from optical identification of the sources detected in ASCA surveys (total ~75deg^2^) with a flux limit of (1-3)x10^-13^erg/s/cm^2^ (2-10keV). The sample covers the AGNs at 0.1<~z<~1 with L_2-10keV_=10^42^-10^46^erg/s with very high completeness. The near-infrared photometric data of the sample are obtained from the Two Micron All Sky Survey (2MASS, Cat. <II/246>) and observations with Kitt Peak National Observatory 2.1m telescope and the University of Hawaii 2.2m telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/22
- Title:
- NIR galaxy cluster candidates in the SPT survey
- Short Name:
- J/ApJ/761/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the ground- and space-based optical and near-infrared (NIR) follow-up of 224 galaxy cluster candidates detected with the Sunyaev-Zel'dovich (SZ) effect in the 720deg^2^ of the South Pole Telescope (SPT) survey completed in the 2008 and 2009 observing seasons. We use the optical/NIR data to establish whether each candidate is associated with an overdensity of galaxies and to estimate the cluster redshift. Most photometric redshifts are derived through a combination of three different cluster redshift estimators using red-sequence galaxies, resulting in an accuracy of {Delta}z/(1+z)=0.017, determined through comparison with a subsample of 57 clusters for which we have spectroscopic redshifts. We successfully measure redshifts for 158 systems and present redshift lower limits for the remaining candidates. The redshift distribution of the confirmed clusters extends to z=1.35 with a median of z_med_=0.57. Approximately 18% of the sample with measured redshifts lies at z>0.8. We estimate a lower limit to the purity of this SPT SZ-selected sample by assuming that all unconfirmed clusters are noise fluctuations in the SPT data. We show that the cumulative purity at detection significance {xi}>5 ({xi}>4.5) is >=95% (>=70%). We present the red brightest cluster galaxy (rBCG) positions for the sample and examine the offsets between the SPT candidate position and the rBCG. The radial distribution of offsets is similar to that seen in X-ray-selected cluster samples, providing no evidence that SZ-selected cluster samples include a different fraction of recent mergers from X-ray-selected cluster samples.
- ID:
- ivo://CDS.VizieR/J/ApJS/239/22
- Title:
- NIR obs. of X-ray AGNs in COSMOS, SXDS & E-CDF-S
- Short Name:
- J/ApJS/239/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-IR spectroscopy in the J- and H-bands for a large sample of 243 X-ray-selected, moderate-luminosity Type 1 active galactic nuclei (AGNs) in the COSMOS, SXDS, and E-CDF-S survey fields using the multi-object spectrograph Subaru/FMOS. Our sample covers the redshift range 0.5<=z<=3.0 and X-ray luminosity range of 10^43^<=L_[2-10keV]_<=10^45^erg/s. We provide emission-line properties and derived virial black hole mass estimates, bolometric luminosities, and Eddington ratios, based on H{alpha} (211), H{beta} (63), and MgII (4). We compare line widths, luminosities, and black hole mass estimates from H{alpha} and H{beta}, and augment these with commensurate measurements of MgII and CIV detected in optical spectra. We demonstrate the robustness of using H{alpha}, H{beta}, and MgII as reliable black hole mass estimators for high-z moderate-luminosity AGNs, while the use of CIV is prone to large uncertainties (>=0.4dex). We extend a recently proposed correction based on the CIV blueshift to lower luminosities and black hole masses. While our sample shows an improvement in their CIV black hole mass estimates, the deficit of high blueshift sources reduces its overall importance for moderate-luminosity AGNs compared to the most luminous quasars. In addition, we revisit luminosity correlations between Lbol, L_[2-10keV]_, L[OIII], L5100, and LH{alpha} and find them to be consistent with a simple empirical model, based on a small number of well-established scaling relations. Finally, we highlight our highest redshift AGN, CID 781, at z=4.6, which has the lowest black hole mass (~10^8^M_{sun}_) among current near-IR samples at this redshift and is in a state of fast growth.
- ID:
- ivo://CDS.VizieR/J/ApJ/796/7
- Title:
- NIR spectral analysis of star-forming galaxies
- Short Name:
- J/ApJ/796/7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we follow up on our previous detection of nuclear ionized outflows in the most massive (log(M_*_/M_{sun}_)>=10.9) z~1-3 star-forming galaxies (SFGs) by increasing the sample size by a factor of six (to 44 galaxies above log(M_*_/M_{sun}_)>=10.9) from a combination of the SINS/zC-SINF, LUCI, GNIRS, and KMOS^3D^ spectroscopic surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/812/66
- Title:
- NIR spectra of 5 red quasars at 0.5<z<0.9
- Short Name:
- J/ApJ/812/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Red quasars are thought to be an intermediate population between merger-driven star-forming galaxies in dust-enshrouded phase and normal quasars. If so, they are expected to have high accretion ratios, but their intrinsic dust extinction hampers reliable determination of Eddington ratios. Here, we compare the accretion rates of 16 red quasars at z~0.7 to those of normal type 1 quasars at the same redshift range. The red quasars are selected by their red colors in optical through near-infrared (NIR) and radio detection. The accretion rates of the red quasars are derived from the P{beta} line in NIR spectra, which is obtained by the SpeX on the Infrared Telescope Facility in order to avoid the effects of dust extinction. We find that the measured Eddington ratios (L_bol_/L_Edd_~=0.69) of red quasars are significantly higher than those of normal type 1 quasars, which is consistent with a scenario in which red quasars are the intermediate population and the black holes of red quasars grow very rapidly during such a stage.
- ID:
- ivo://CDS.VizieR/J/ApJ/806/L35
- Title:
- NIR spectroscopy of COSMOS FIR galaxies
- Short Name:
- J/ApJ/806/L35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used FMOS on Subaru to obtain near-infrared spectroscopy of 123 far-infrared-selected galaxies in COSMOS and the key rest-frame optical emission lines. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that span a range of metallicities in comparison with previous optically selected surveys, and thus has a higher active galactic nucleus (AGN) fraction and better samples the AGN branch. We establish the presence of AGNs and starbursts in this sample of (U)LIRGs selected as Herschel-PACS and Spitzer-MIPS detections in two redshift bins (z~0.7 and z~1.5) and test the redshift dependence of diagnostics used to separate AGNs from star formation dominated galaxies. In addition, we construct a low-redshift (z~0.1) comparison sample of infrared-selected galaxies and find that the evolution from z~1.5 to today is consistent with an evolving AGN selection line and a range of ISM conditions and metallicities from the models of Kewley et al. (2013ApJ...774L..10K). We find that a large fraction of (U)LIRGs are BPT-selected AGNs using their new redshift-dependent classification line. We compare the position of known X-ray-detected AGNs (67 in total) with the BPT selection and find that the new classification line accurately selects most of these objects (>70%). Furthermore, we identify 35 new (likely obscured) AGNs not selected as such by their X-ray emission. Our results have direct implications for AGN selection at higher redshift with either current (MOSFIRE, KMOS) or future (PFS, MOONS) spectroscopic efforts with near-infrared spectral coverage.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/55
- Title:
- NIR spectroscopy of 1.5<z<3.5 broad-band QSOs
- Short Name:
- J/ApJ/817/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the rest-frame optical properties of 74 luminous (L_bol_=10^46.2-48.2^erg/s), 1.5<z<3.5 broad-line quasars with near-IR (JHK) slit spectroscopy. Systemic redshifts based on the peak of the [OIII]{lambda}5007 line reveal that redshift estimates from the rest-frame UV broad emission lines (mostly MgII) are intrinsically uncertain by ~200km/s (measurement errors accounted for). The overall full-width-at-half-maximum of the narrow [OIII] line is ~1000km/s on average. A significant fraction of the total [OIII] flux (~40%) is in a blueshifted wing component with a median velocity offset of ~700km/s, indicative of ionized outflows within a few kpc from the nucleus; we do not find evidence of significant [OIII] flux beyond ~10kpc in our slit spectroscopy. The [OIII] line is noticeably more asymmetric and weaker than that in typical less luminous low-z quasars. However, when matched in quasar continuum luminosity, low-z quasars have similar [OIII] profiles and strengths as these high-z systems. Therefore the exceptionally large width and blueshifted wing, and the relatively weak strength of [OIII] in high-z luminous quasars are mostly a luminosity effect rather than redshift evolution. The H{beta}-[OIII] region of these high-z quasars displays a similar spectral diversity and Eigenvector 1 correlations with anti-correlated [OIII] and optical FeII strengths, as seen in low-z quasars; but the average broad H{beta} width is larger by 25% than typical low-z quasars, indicating more massive black holes in these high-z systems. These results highlight the importance of understanding [OIII] in the general context of quasar parameter space in order to understand quasar feedback in the form of [OIII] outflows. The calibrated one-dimensional near-IR spectra are made publicly available, along with a composite spectrum.
