- ID:
- ivo://CDS.VizieR/J/MNRAS/462/2878
- Title:
- SFR & AGN in most luminous local universe LINERs
- Short Name:
- J/MNRAS/462/2878
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work presents the properties of 42 objects in the group of the most luminous, highest star formation rate (SFR) low-ionization nuclear emission-line regions (LINERs) at z=0.04-0.11. We obtained long-slit spectroscopy of the nuclear regions for all sources, and FIR data (Herschel and IRAS) for 13 of them. We measured emission-line intensities, extinction, stellar populations, stellar masses, ages, active galactic nuclei (AGN) luminosities, and SFRs. We find considerable differences from other low-redshift LINERs, in terms of extinction, and general similarity to star-forming galaxies. We confirm the existence of such luminous LINERs in the local universe, after being previously detected at z~0.3 by Tommasin et al. The median stellar mass of these LINERs corresponds to 6-7x10^10^M_{sun}_ which was found in previous work to correspond to the peak of relative growth rate of stellar populations and therefore for the highest SFRs. Other LINERs although showing similar AGN luminosities have lower SFR. We find that most of these sources have LAGN~LSF suggesting co-evolution of black hole and stellar mass. In general, the fraction of local LINERs on the main sequence of star-forming galaxies is related to their AGN luminosity.
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- ID:
- ivo://CDS.VizieR/J/A+A/581/A124
- Title:
- SFR IRAS 05137+3919 star and jet multiplicity
- Short Name:
- J/A+A/581/A124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the complex high-mass star forming region IRAS05137+3919 (also known as Mol8), where multiple jets and a rich stellar cluster have been described in previous works. Our goal is to determine the number of jets and shed light on their origin, and thus determine the nature of the young stars powering these jets. We also wish to analyse the stellar clusters by resolving the brightest group of stars. The star forming region was observed in various tracers and the results were complemented with ancillary archival data. The new data represent a substantial improvement over previous studies both in resolution and frequency coverage. In particular, adaptive optics provides us with an angular resolution of 80mas in the near IR, while new mid- and far-IR data allow us to sample the peak of the spectral energy distribution and thus reliably estimate the bolometric luminosity. Thanks to the near-IR continuum and millimetre line data we can determine the structure and velocity field of the bipolar jets and outflows in this star forming region. We also find that the stars are grouped into three clusters and the jets originate in the richest of these, whose luminosity is ~2.4x10^4^L_{sun}_. Interestingly, our high-resolution near-IR images allow us to resolve one of the two brightest stars (A and B) of the cluster into a double source (A1+A2). We confirm that there are two jets and establish that they are powered by B-type stars belonging to cluster C1. On this basis and on morphological and kinematical arguments, we conclude that the less extended jet is almost perpendicular to the line of sight and that it originates in the brightest star of the cluster, while the more extended one appears to be associated with the more extincted, double source A1+A2. We propose that this is not a binary system, but a small bipolar reflection nebula at the root of the large-scale jet, outlining a still undetected circumstellar disk. The gas kinematics on a scale of ~0.2pc seems to support our hypothesis, because it appears to trace rotation about the axis of the associated jet.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/118
- Title:
- SFR-M_*_ relation from ZFOURGE
- Short Name:
- J/ApJ/817/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore star formation histories (SFHs) of galaxies based on the evolution of the star formation rate stellar mass relation (SFR-M_*_). Using data from the FourStar Galaxy Evolution Survey (ZFOURGE) in combination with far-IR imaging from the Spitzer and Herschel observatories we measure the SFR-M_*_ relation at 0.5<z<4. Similar to recent works we find that the average infrared spectral energy distributions of galaxies are roughly consistent with a single infrared template across a broad range of redshifts and stellar masses, with evidence for only weak deviations. We find that the SFR-M_*_ relation is not consistent with a single power law of the form SFR{propto}M_{star}_^{alpha}^ at any redshift; it has a power law slope of {alpha}~1 at low masses, and becomes shallower above a turnover mass (M_0_) that ranges from 10^9.5^ to 10^10.8^M_{sun}_, with evidence that M_0_ increases with redshift. We compare our measurements to results from state-of-the-art cosmological simulations, and find general agreement in the slope of the SFR-M_*_ relation albeit with systematic offsets. We use the evolving SFR-M_*_ sequence to generate SFHs, finding that typical SFRs of individual galaxies rise at early times and decline after reaching a peak. This peak occurs earlier for more massive galaxies. We integrate these SFHs to generate mass growth histories and compare to the implied mass growth from the evolution of the stellar mass function (SMF). We find that these two estimates are in broad qualitative agreement, but that there is room for improvement at a more detailed level. At early times the SFHs suggest mass growth rates that are as much as 10x higher than inferred from the SMF. However, at later times the SFHs under-predict the inferred evolution, as is expected in the case of additional growth due to mergers.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A84
- Title:
- S4G disk galaxies stellar mass distribution
- Short Name:
- J/A+A/596/A84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Models of galaxy formation in a cosmological framework require observational constraints to be tested against, such as the average stellar density profiles (and their dispersion) as a function of fundamental galaxy properties (e.g. the total stellar mass). Simulation models predict that the torques produced by stellar bars efficiently redistribute the stellar and gaseous material inside the disk, pushing it outwards or inwards depending on whether it is beyond or inside the bar corotation resonance radius, respectively. Bars themselves are expected to evolve, getting longer and narrower as they trap particles from the disk and slow down their rotation speed. We use 3.6um photometry from the Spitzer Survey of Stellar Structure in Galaxies (S4G) to trace the stellar distribution in nearby disk galaxies (z~~0) with total stellar masses 10^8.5^<=M*/M_{sun}_<=10^11^ and mid IR Hubble types -3<=T<=10. We characterize the stellar density profiles ({SIGMA}*), the stellar contribution to the rotation curves (V3.6um) and the m=2 Fourier amplitudes (A2) as a function of M* and T. We also describe the typical shapes and strengths of stellar bars in the S4G sample and link their properties to the total stellar mass and morphology of their host galaxy. For 1154 S4G galaxies with disk inclinations lower than 65{deg}, we perform a Fourier decomposition and rescale their images to a common frame determined by the size in physical units, by their disk scalelength, and for 748 barred galaxies by both the length and orientation of their bars. We stack the resized density profiles and images to obtain statistically representative average stellar disks and bars in bins of M* and T. Based on the radial force profiles of individual galaxies we calculate the mean stellar contribution to the circular velocity. We also calculate average A2 profiles, where the radius is normalized to R25.5. Furthermore, we infer the gravitational potentials from the synthetic bars to obtain the tangential-to-radial force ratio (QT) and A2 profiles in the different bins. We also apply ellipse fitting to quantitatively characterize the shape of the bar stacks. For M*>=10^9^M_{sun}_, we find a significant difference in the stellar density profiles of barred and non-barred systems: (i) disks in barred galaxies show larger scalelengths (hR) and fainter extrapolated central surface brightnesses ({SIGMA}0), (ii) the mean surface brightness profiles ({SIGMA}*) of barred and non-barred galaxies intersect each other slightly beyond the mean bar length, most likely at the bar corotation, and (iii) the central mass concentration of barred galaxies is larger (by almost a factor 2 when T<=5) than in their non-barred counterparts. The averaged {SIGMA}* profiles follow an exponential slope down to at least ~10M_{sun}_/pc^2^, which is the typical depth beyond which the sample coverage in the radial direction starts to drop. Central mass concentrations in massive systems (>=10^10^M_{sun}_) are substantially larger than in fainter galaxies, and their prominence scales with T. This segregation also manifests in the inner slope of the mean stellar component of the circular velocity: lenticular (S0) galaxies present the most sharply rising V3.6um . Based on the analysis of bar stacks, we show that early- and intermediate-type spirals (0<=T<5) have intrinsically narrower bars compared to later types and S0s, whose bars are oval-shaped. We show a clear agreement between galaxy family and quantitative estimates of bar strength. In early- and intermediate-type spirals, A2 is larger within and beyond the typical bar region among barred galaxies, compared to the non-barred subsample. Strongly barred systems also tend to have larger A2 amplitudes at all radii than their weakly barred counterparts. Using near-IR wavelengths (S4G 3.6um), we provide observational constraints for galaxy formation models to be checked against. In particular, we calculate the mean stellar density profiles, and the disk(+bulge) component of the rotation curve (and their dispersion) in bins of M* and T. We find evidence for bar-induced secular evolution of disk galaxies, in terms of disk spreading and enhanced central mass concentration. We also obtain average bars (2-D), and we show that bars hosted by early-type galaxies are more centrally concentrated and have larger density amplitudes than their late-type counterparts.
- ID:
- ivo://CDS.VizieR/J/ApJS/217/32
- Title:
- S4G galaxy morphologies in the CVRHS system
- Short Name:
- J/ApJS/217/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Survey of Stellar Structure in Galaxies (S^4^G) is the largest available database of deep, homogeneous middle-infrared (mid-IR) images of galaxies of all types. The survey, which includes 2352 nearby galaxies, reveals galaxy morphology only minimally affected by interstellar extinction. This paper presents an atlas and classifications of S^4^G galaxies in the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system. The CVRHS system follows the precepts of classical de Vaucouleurs morphology, modified to include recognition of other features such as inner, outer, and nuclear lenses, nuclear rings, bars, and disks, spheroidal galaxies, X patterns and box/peanut structures, OLR subclass outer rings and pseudorings, bar ansae and barlenses, parallel sequence late-types, thick disks, and embedded disks in 3D early-type systems. We show that our CVRHS classifications are internally consistent, and that nearly half of the S^4^G sample consists of extreme late-type systems (mostly bulgeless, pure disk galaxies) in the range Scd-Im. The most common family classification for mid-IR types S0/a to Sc is SA while that for types Scd to Sm is SB. The bars in these two type domains are very different in mid-IR structure and morphology. This paper examines the bar, ring, and type classification fractions in the sample, and also includes several montages of images highlighting the various kinds of "stellar structures" seen in mid-IR galaxy morphology.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/4
- Title:
- S4G pipeline 4: multi-component decompositions
- Short Name:
- J/ApJS/219/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Survey of Stellar Structure in Galaxies (S^4^G) is a deep 3.6 and 4.5{mu}m imaging survey of 2352 nearby (<40Mpc) galaxies. We describe the S^4^G data analysis pipeline 4, which is dedicated to two-dimensional structural surface brightness decompositions of 3.6{mu}m images, using GALFIT3.0. Besides automatic 1-component Sersic fits, and 2-component Sersic bulge + exponential disk fits, we present human-supervised multi-component decompositions, which include, when judged appropriate, a central point source, bulge, disk, and bar components. Comparison of the fitted parameters indicates that multi-component models are needed to obtain reliable estimates for the bulge Sersic index and bulge-to-total light ratio (B/T), confirming earlier results. Here, we describe the preparations of input data done for decompositions, give examples of our decomposition strategy, and describe the data products released via IRSA and via our web page (www.oulu.fi/astronomy/S4G_PIPELINE4/MAIN). These products include all the input data and decomposition files in electronic form, making it easy to extend the decompositions to suit specific science purposes. We also provide our IDL-based visualization tools (GALFIDL) developed for displaying/running GALFIT-decompositions, as well as our mask editing procedure (MASK_EDIT) used in data preparation. A detailed analysis of the bulge, disk, and bar parameters derived from multi-component decompositions will be published separately.
- ID:
- ivo://CDS.VizieR/J/A+A/618/L10
- Title:
- SgrA* orbital motions with GRAVITY
- Short Name:
- J/A+A/618/L10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of continuous positional and polarization changes of the compact source SgrA* in high states ('flares') of its variable near- infrared emission with the near-infrared GRAVITY-Very Large Telescope Interferometer (VLTI) beam-combining instrument. In three prominent bright flares, the position centroids exhibit clockwise looped motion on the sky, on scales of typically 150 micro-arcseconds over a few tens of minutes, corresponding to about 30% the speed of light. At the same time, the flares exhibit continuous rotation of the polarization angle, with about the same 45(+/-15)-minute period as that of the centroid motions. Modelling with relativistic ray tracing shows that these findings are all consistent with a near face-on, circular orbit of a compact polarized 'hot spot' of infrared synchrotron emission at approximately six to ten times the gravitational radius of a black hole of 4 million solar masses. This corresponds to the region just outside the innermost, stable, prograde circular orbit (ISCO) of a Schwarzschild-Kerr black hole, or near the retrograde ISCO of a highly spun-up Kerr hole. The polarization signature is consistent with orbital motion in a strong poloidal magnetic field.
- ID:
- ivo://CDS.VizieR/J/A+A/467/73
- Title:
- 3{sigma} hard sample of XMDS survey
- Short Name:
- J/A+A/467/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample with wide multiwavelength coverage. We selected a sample of 136 X-ray sources detected at a significance of >=3{sigma} in the 2-10keV band (F_2-10_>~10^-14^erg/cm^2^/s) in a ~1deg^2^ area in the XMM Medium Deep Survey (XMDS, Cat. <J/A+A/439/413>). The XMDS area is covered with optical photometry from the VVDS and CFHTLS surveys and infrared Spitzer data from the SWIRE survey. Based on the X-ray luminosity and X-ray to optical ratio, 132 sources are likely AGN, of which 122 have unambiguous optical - IR identification. The observed optical and IR spectral energy distributions of all identified sources are fitted with AGN/galaxy templates in order to classify them and compute photometric redshifts. X-ray spectral analysis is performed individually for sources with a sufficient number of counts and using a stacking technique for subsamples of sources at different flux levels. Hardness ratios are used to estimate X-ray absorption in individual weak sources.
- ID:
- ivo://CDS.VizieR/J/A+A/426/97
- Title:
- SIMBA survey. 1.2-mm/IRAS sources
- Short Name:
- J/A+A/426/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a 1.2mm continuum emission survey toward 146 IRAS sources thought to harbour high-mass star forming regions. The sources have FIR colors typical of UCHII regions and were detected in the CS (2-1) line survey of Bronfman et al. (1996, Cat. J/A+AS/115/81). Regions of 15'x10', centered on each IRAS source, were mapped with an angular resolution of ~24", using the SIMBA array on the SEST telescope. 1.2mm emission was detected toward all IRAS sources. We find that the dust cores associated with these sources have typical sizes of 0.4pc and masses of 5x10^3^M_{sun}. Dust temperatures and luminosities, derived from the SED, are typically 32K and 2.3x10^5^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/543/A61
- Title:
- SINFONI data cube of NGC 7552
- Short Name:
- J/A+A/543/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Approximately 20% of all spiral galaxies display starburst activity in nuclear rings of a few hundred parsecs in diameter. It is our main aim to investigate how the starburst ignites and propagates within the ring, leading to the formation of massive stellar clusters. We observed the ring galaxy NGC 7552 with the mid-infrared (MIR) instrument VISIR at an angular resolution of 0.3"-0.4" and with the near-infrared (NIR) integral-field spectrograph SINFONI on the VLT, and complement these observations with data from ISO and Spitzer. The starburst ring is clearly detected at MIR wavelengths at the location of the dust-extincted, dark ring seen in HST observations. This "ring", however, is a rather complex annular region of more than 100 parsec width. We find a large fraction of diffuse [NeII] and PAH emission in the central region that is not associated with the MIR peaks on spatial scales of ~30pc. We do not detect MIR emission from the nucleus of NGC 7552, which is very prominent at optical and NIR continuum wavelengths. However, we have identified nine unresolved MIR peaks within the ring. The average extinction of these peaks is A_V_=7.4 and their total infrared luminosity is L_IR_=2.1x10^10^L_{sun}_. The properties of these peaks are typical for MIR-selected massive clusters found in other galaxies. The ages of the MIR-selected clusters are in the range of 5.9+/-0.3Myr. The age spread among the clusters of 0.8Myr is small compared to the travel time of ~5.6Myr for half an orbit within the starburst ring. We find no strong evidence for a scenario where the continuous inflow of gas leads to the ongoing formation of massive clusters at the contact points between galactic bar and starburst ring. Instead, it appears more likely that the gas density build up more gradually over larger ring segments, and that the local physical conditions govern cluster formation. We note that the fundamental limitation on the accurate derivation of cluster age, mass and initial mass function slope is the lack of higher angular resolution. Resolving the highly embedded, massive clusters requires milli-arcsecond resolution at infrared wavelengths, which will be provided by the next generation of instruments on extremely large telescopes (ELTs).