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- ID:
- ivo://CDS.VizieR/J/ApJ/791/113
- Title:
- MIR-selected quasar parameters
- Short Name:
- J/ApJ/791/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a catalog of 391 mid-infrared-selected (MIR; 24 {mu}m) broad-emission-line (BEL; type 1) quasars in the 22 deg^2^ SWIRE Lockman Hole field. This quasar sample is selected in the MIR from Spitzer MIPS with S_24_> 400 {mu}Jy, jointly with an optical magnitude limit of r(AB) < 22.5 for broad line identification. The catalog is based on MMT and Sloan Digital Sky Survey (SDSS) spectroscopy to select BEL quasars, extending the SDSS coverage to fainter magnitudes and lower redshifts, and recovers a more complete quasar population. The MIR-selected quasar sample peaks at z ~ 1.4 and recovers a significant and constant (20%) fraction of extended objects with SDSS photometry across magnitudes, which were not included in the SDSS quasar survey dominated by point sources. This sample also recovers a significant population of z < 3 quasars at i > 19.1. We then investigate the continuum luminosity and line profiles of these MIR quasars, and estimate their virial black hole masses and the Eddington ratios. The supermassive black hole mass shows evidence of downsizing, although the Eddington ratios remain constant at 1 < z < 4. Compared to point sources in the same redshift range, extended sources at z < 1 show systematically lower Eddington ratios. The catalog and spectra are publicly available online.
- ID:
- ivo://CDS.VizieR/J/ApJ/701/1123
- Title:
- MIR spectroscopic catalog of 150 galaxies
- Short Name:
- J/ApJ/701/1123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of mid-infrared (MIR) spectra of 150 infrared (IR) luminous galaxies in the Spitzer extragalactic first look survey obtained with the IR spectrograph on board the Spitzer Space Telescope. The sample is selected to be brighter than ~0.9mJy at 24um and it has a redshift distribution in the range [0.3, 3.5], with a peak at z=1. It primarily comprises ultraluminous IR galaxies (ULIRGs) at z>~1 and luminous IR galaxies at z<1, as estimated from their monochromatic rest-frame 14um luminosities. The number of sources with spectra that are dominated by an active galactic nucleus (AGN) continuum is 49, while 39 sources have strong, star formation related features.
- ID:
- ivo://CDS.VizieR/J/ApJ/822/109
- Title:
- MIR view of polar dust emission in local AGNs
- Short Name:
- J/ApJ/822/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent mid-infrared (MIR) interferometric observations have shown that in a few active galactic nuclei (AGNs) the bulk of the infrared emission originates from the polar region above the putative torus, where only a little dust should be present. Here, we investigate whether such strong polar dust emission is common in AGNs. Out of 149 Seyferts in the MIR atlas of local AGNs, 21 show extended MIR emission on single-dish images. In 18 objects, the extended MIR emission aligns with the position angle (PA) of the system axis, established by [O III], radio, polarization, and maser-based PA measurements. The relative amount of resolved MIR emission is at least 40% and scales with the [O IV] fluxes, implying a strong connection between the extended continuum and [O IV] emitters. These results together with the radio-quiet nature of the Seyferts support the scenario that the bulk of MIR emission is emitted by dust in the polar region and not by the torus, which would demand a new paradigm for the infrared emission structure in AGNs. The current low detection rate of polar dust in the AGNs of the MIR atlas is explained by the lack of sufficient high-quality MIR data and the requirements on the orientation, strength of narrow-line region, and distance of the AGNs. The James Webb Space Telescope will enable much deeper nuclear MIR studies with comparable angular resolution, allowing us to resolve the polar emission and surroundings in most of the nearby AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJ/846/71
- Title:
- M51 ISM structures from the CO maps of PAWS
- Short Name:
- J/ApJ/846/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the structure of molecular gas at 40pc resolution to the ability of gas to form stars across the disk of the spiral galaxy M51. We break the PdBI Arcsecond Whirlpool Survey (PAWS; Schinnerer+ 2013ApJ...779...42S) into 370pc and 1.1kpc resolution elements, and within each we estimate the molecular gas depletion time ({tau}_Dep_^mol^), the star-formation efficiency per free-fall time ({epsilon}_ff_), and the mass-weighted cloud-scale (40pc) properties of the molecular gas: surface density, {Sigma}, line width, {sigma}, and b={Sigma}/{sigma}^2^{propto}{alpha}_vir_^-1^, a parameter that traces the boundedness of the gas. We show that the cloud-scale surface density appears to be a reasonable proxy for mean volume density. Applying this, we find a typical star-formation efficiency per free-fall time, {epsilon}_ff_(<{Sigma}_40pc_>)~0.3%-0.36%, lower than adopted in many models and found for local clouds. Furthermore, the efficiency per free-fall time anti-correlates with both {Sigma} and {sigma}, in some tension with turbulent star-formation models. The best predictor of the rate of star formation per unit gas mass in our analysis is b={Sigma}/{sigma}^2^, tracing the strength of self-gravity, with {tau}_Dep_^mol^{propto}b^-0.9^. The sense of the correlation is that gas with stronger self-gravity (higher b) forms stars at a higher rate (low {tau}_Dep_^mol^). The different regions of the galaxy mostly overlap in {tau}_Dep_^mol^ as a function of b, so that low b explains the surprisingly high {tau}_Dep_^mol^ found toward the inner spiral arms found by Meidt et al. (2013ApJ...779...45M).
- ID:
- ivo://CDS.VizieR/J/A+AS/110/131
- Title:
- Mixed pairs of galaxies. I.
- Short Name:
- J/A+AS/110/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present data from a kinematic and photometric study of six mixed pairs. High resolution rotation and velocity dispersion curves, for both gas and stellar components, are presented. Slit orientations were along the major axis of the spiral and, in most of the cases, along the line connecting the galaxy nuclei. B and V luminosity and geometrical profiles and photometric parameters including effective radius and disk scale length are also presented.
2327. M87 jet VLBI images
- ID:
- ivo://CDS.VizieR/J/A+A/616/A188
- Title:
- M87 jet VLBI images
- Short Name:
- J/A+A/616/A188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Messier 87 (M87) is one of the nearest radio galaxies with a prominent jet extending from sub-pc to kpc scales. Because of its proximity and the large mass of its central black hole (BH), it is one of the best radio sources for the study of jet formation. We study the physical conditions near the jet base at projected separations from the BH of ~7-100 Schwarzschild radii (Rsch). Global mm-VLBI Array (GMVA) observations at 86GHz ({lambda}=3.5mm) provide an angular resolution of ~50{mu}arcsec, which corresponds to a spatial resolution of only 7Rsch and reach the small spatial scale. We use five GMVA data sets of M87 obtained from 2004 to 2015 and present new high angular resolution VLBI maps at 86GHz. In particular, we focus on the analysis of the brightness temperature, the jet ridge lines, and the ratio of jet to counter-jet. The imaging reveals a parabolically expanding limb-brightened jet which emanates from a resolved VLBI core of ~(8-13)Rsch in size. The observed brightness temperature of the core at any epoch is ~(1-3)x10^10^K, which is below the equipartition brightness temperature and suggests magnetic energy dominance at the jet base. We estimate the diameter of the jet at its base to be ~5Rsch assuming a self-similar jet structure. This suggests that the sheath of the jet may be anchored in the very inner portion of the accretion disk. The image stacking reveals faint emission at the center of the edge-brightened jet on sub-pc scales. We discuss its physical implication within the context of the spine-sheath structure of the jet.
- ID:
- ivo://CDS.VizieR/J/ApJS/103/331
- Title:
- mJy radio sources at 1.4 GHz
- Short Name:
- J/ApJS/103/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From the 1.4GHz radio survey of Condon, Dickey, & Salpeter (Cat. <J/AJ/99/1071>) in a region much devoid of rich galaxy clusters at redshifts z<0.43 we selected a "distant" sample of 57 radio sources complete to a 1.4GHz flux density of 35mJy and a "nearby" sample of 36 mostly weaker radio sources which are optically brighter than B~19mag. Our ultimate goals are (1) to study the radio, optical, and near-IR properties of those high-redshift (z~1), moderate-power radio sources in the distant sample and to compare them with that of more powerful radio sources, and (2) to make a comparison of primarily noncluster radio sources in the nearby sample with a companion survey of radio sources in a pair of rich superclusters at z~0.1. In this first paper of a series, we report our new C-array VLA continuum snapshots at 4.86GHz and optical R-band CCD imaging photometry for these two samples and tabulate the observational results on individual sources. Some direct sample statistical properties are also discussed in the paper and summarized as follows: (1) The distant sample: (a) The sample median flux density at 1.4GHz is about 65mJy. (b) The majority (80%) of the sample sources have a steep spectrum between 1.4 and 4.86GHz with a spectral index around 0.9. Nineteen (90%) of the 21 sources that are fully resolved at 4.86 GHz (i.e., angular sizes {theta}>11") have a radio morphology of Fanaroff-Riley (FR) II type. (c) Thirty-seven (88%) of the 42 optically imaged sample sources were optically identified to a limiting R-band magnitude of R~23.5mag. About 15% of the identified radio sources appear to be point sources, and the others are extended galaxies with an appearance similar to nearby elliptical galaxies. (d) Twenty-eight (76%) of the optically identified sources have R>20mag, suggesting that these are probably distant (z>0.8), with a redshift distribution peaking at z~1, where their radio luminosities are about 10 times the break power between the FR I and II classes. (e) We found no strong evidence for the radio and optical axes of the resolved radio sources (i.e., {theta}>5") to be correlated or anticorrelated, nor any evidence for strong clustering around sample radio sources on average. (2) The nearby sample: except for R<15, the sample is dominated by elliptical galaxies with 16<R<18.5mag and a spectral index distribution similar to that of the distant sample. Based on the radial distribution of optical objects around each radio source, we found that the average radio source environment becomes richer from that characteristic of galaxy groups for R<17mag (z<0.2) to that of galaxy groups to clusters at R>18mag (z>0.3) .
- ID:
- ivo://CDS.VizieR/J/A+A/623/A171
- Title:
- Mkn 848 MaNGA 3-D data cube
- Short Name:
- J/A+A/623/A171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characterisation of galaxy-scale outflows in terms of their multi-phase and multi-scale nature, amount, and effects of flowing material is crucial to place constraints on models of galaxy formation and evolution. This study can proceed only with the detailed investigation of individual targets. We present a spatially resolved spectroscopic optical data analysis of Mkn 848, a complex system consisting of two merging galaxies at z~0.04 that are separated by a projected distance of 7.5kpc. Motivated by the presence of a multi-phase outflow in the north-west system revealed by the SDSS integrated spectrum, we analysed the publicly available MaNGA data, which cover almost the entire merging system, to study the kinematic and physical properties of cool and warm gas in detail. Galaxy-wide outflowing gas in multiple phases is revealed for the first time in the two merging galaxies. We also detect spatially resolved resonant NaID emission associated with the outflows. The derived outflow energetics (mass rate, and kinetic and momentum power) may be consistent with a scenario in which both winds are accelerated by stellar processes and AGN activity, although we favour an AGN origin given the high outflow velocities and the ionisation conditions observed in the outflow regions. Further deeper multi-wavelength observations are required, however, to better constrain the nature of these multi-phase outflows. Outflow energetics in the north-west system are strongly different between the ionised and atomic gas components, the latter of which is associated with mass outflow rate and kinetic and momentum powers that are one or two dex higher; those associated with the south-east galaxy are instead similar. Strong kiloparsec-scale outflows are revealed in an ongoing merger system, suggesting that feedback can potentially impact the host galaxy even in the early merger phases. The characterisation of the neutral and ionised gas phases has proved to be crucial for a comprehensive study of the outflow phenomena.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/140
- Title:
- M81, LMC and 3C 273/Coma 17-60keV obs.
- Short Name:
- J/MNRAS/459/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a deep survey of three extragalactic fields, M81 (exposure of 9.7Ms), Large Magellanic Cloud (6.8 Ms) and 3C 273/Coma (9.3Ms), in the hard X-ray (17-60keV) energy band with the IBIS telescope onboard the INTEGRAL observatory, based on 12 years of observations (2003-2015). The combined survey reaches a 4{sigma} peak sensitivity of 0.18mCrab (2.6x10^-12^erg/s/cm^2^) and sensitivity better than 0.25 and 0.87mCrab over 10 per cent and 90 per cent of its full area of 4900 deg^2^, respectively. We have detected in total 147 sources at S/N>4{sigma}, including 37 sources observed in hard X-rays for the first time. The survey is dominated by extragalactic sources, mostly active galactic nuclei (AGN). The sample of identified sources contains 98 AGN (including 64 Seyfert galaxies, seven low-ionization nuclear emission-line region galaxies, three X-ray bright optically normal galaxies, 16 blazars and eight AGN of unclear optical class), two galaxy clusters (Coma and Abell 3266), 17 objects located in the Large and Small Magellanic Clouds (13 high- and two low-mass X-ray binaries and two X-ray pulsars), three Galactic cataclysmic variables, one ultraluminous X-ray source (M82 X-1) and one blended source (SWIFT J1105.7+5854). The nature of 25 sources remains unknown, so that the survey's identification is currently complete at 83 per cent. We have constructed AGN number-flux relations (log N-log S) and calculated AGN number densities in the local Universe for the entire survey and for each of the three extragalactic fields.
