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2711. PACO faint sources catalog
ID:
ivo://CDS.VizieR/J/MNRAS/416/559
Title:
PACO faint sources catalog
Short Name:
J/MNRAS/416/559
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Planck-ATCA Coeval Observations (PACO) project collected data between 4.5 and 40GHz for 482 sources selected within the Australia Telescope 20GHz (AT20G) catalogue and observed with the Australia Telescope Compact Array. Observations were done almost simultaneously with the Planck satellite, in the period between 2009 July and 2010 August. In this paper, we present and discuss the data for the complete sample of 159 sources with S_AT20G_>200mJy in the South Ecliptic Pole region.
2712. PACO spectrally selected sample
ID:
ivo://CDS.VizieR/J/MNRAS/428/1845
Title:
PACO spectrally selected sample
Short Name:
J/MNRAS/428/1845
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Planck Australia Telescope Compact Array (Planck-ATCA) Co-eval Observations (PACO) have provided multi-frequency (5-40GHz) flux density measurements of complete samples of Australia Telescope 20GHz (AT20G) radio sources at frequencies below and overlapping with Planck frequency bands, almost simultaneously with Planck observations. In this work we analyse the data in total intensity for the spectrally selected PACO sample, a complete sample of 69 sources brighter than S20GHz=200mJy selected from the AT20G survey catalogue to be inverted or upturning between 5 and 20GHz. We study the spectral behaviour and variability of the sample. We use the variability between AT20G (2004-2007) and PACO (2009-2010) epochs to discriminate between candidate High-Frequency Peakers (HFPs) and candidate blazars. The HFPs picked up by our selection criteria have spectral peaks >10GHz in the observer frame and turn out to be rare (<0.5% of the S20GHz>=200mJy sources), consistent with the short duration of this phase implied by the "youth" scenario. Most (=~89%) of blazar candidates have remarkably smooth spectra, well described by a double power law, suggesting that the emission in the PACO frequency range is dominated by a single emitting region. Sources with peaked PACO spectra show a decrease of the peak frequency with time at a mean rate of -3+/-2GHz/yr on an average time-scale of <{tau}>=2.1+/-0.5yr (median: {tau}median=1.3yr). The 5-20GHz spectral indices show a systematic decrease from AT20G to PACO. At higher frequencies spectral indices steepen: the median {alpha}4030 is steeper than the median {alpha}205 by {delta}{alpha}=0.6. Taking further into account the Wide-field Infrared Survey Explorer data we find that the Spectral Energy Distributions (SEDs), {nu}S({nu}), of most of our blazars peak at {nu}SEDp<105GHz; the median peak wavelength is {lambda}SEDp=~93{mu}m. Only six have {nu}SEDp>105GHz.
2713. PACS Evolutionary Probe (PEP-DR1) catalogs
ID:
ivo://CDS.VizieR/J/A+A/532/A90
Title:
PACS Evolutionary Probe (PEP-DR1) catalogs
Short Name:
J/A+A/532/A90
Date:
21 Oct 2021
Publisher:
CDS
Description:
Deep far-infrared photometric surveys studying galaxy evolution and the nature of the cosmic infrared background are a key strength of the Herschel mission. We describe the scientific motivation for the PACS Evolutionary Probe (PEP) guaranteed time key program and its role within the entire set of Herschel surveys, and the field selection that includes popular multiwavelength fields such as GOODS, COSMOS, Lockman Hole (LH), ECDFS (Extended Chandra Deep Field South), and EGS (Extended Groth Strip). We present results from the deepest Herschel-PACS (Photodetector Array Camera and Spectrometer) far-infrared blank field extragalactic survey, obtained by combining observations of the GOODS (Great Observatories Origins Deep Survey) fields from the PACS Evolutionary Probe (PEP) and GOODS-Herschel key programmes.
2714. PACS observations of Herschel-BAT sample
ID:
ivo://CDS.VizieR/J/ApJ/794/152
Title:
PACS observations of Herschel-BAT sample
Short Name:
J/ApJ/794/152
Date:
21 Oct 2021
Publisher:
CDS
Description:
Far-Infrared (FIR) photometry from the Photodetector Array Camera and Spectrometer on the Herschel Space Observatory is presented for 313 nearby, hard X-ray selected galaxies from the 58 month Swift Burst Alert Telescope (BAT) Active Galactic Nuclei catalog. The present data do not distinguish between the FIR luminosity distributions at 70 and 160{mu}m for Seyfert 1 and Seyfert 2 galaxies. This result suggests that if the FIR emission is from the nuclear obscuring material surrounding the accretion disk, then it emits isotropically, independent of orientation. Alternatively, a significant fraction of the 70 and 160{mu}m luminosity could be from star formation, independent of active galactic nucleus (AGN) type. Using a non-parametric test for partial correlation with censored data, we find a statistically significant correlation between the AGN intrinsic power (in the 14-195keV band) and the FIR emission at 70 and 160{mu}m for Seyfert 1 galaxies. We find no correlation between the 14-195keV and FIR luminosities in Seyfert 2 galaxies. The observed correlations suggest two possible scenarios: (1) if we assume that the FIR luminosity is a good tracer of star formation, then there is a connection between star formation and the AGN at sub-kiloparsec scales, or (2) dust heated by the AGN has a statistically significant contribution to the FIR emission. Using a Spearman rank-order analysis, the 14-195keV luminosities for the Seyfert 1 and 2 galaxies are weakly statistically correlated with the F_70_/F_160_ratios.
2715. Padova-Millennium Galaxy and Group Catalogue
ID:
ivo://CDS.VizieR/J/MNRAS/416/727
Title:
Padova-Millennium Galaxy and Group Catalogue
Short Name:
J/MNRAS/416/727
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the construction and describe the properties of the Padova-Millennium Galaxy and Group Catalogue (PM2GC), a galaxy catalogue representative of the general field population in the local Universe. We characterize galaxy environments by identifying galaxy groups at 0.04<=z<=0.1 with a Friends-of-Friends (FoF) algorithm using a complete sample of 3210 galaxies brighter than M_B_=-18.7 taken from the Millennium Galaxy Catalogue (MGC, Liske et al., 2003, Cat. VII/240), a 38deg^2^ image photometric and spectroscopic equatorial survey. We identified 176 groups with at least three members, comprising in total 1057 galaxies and representing ~43 per cent of the general field population in that redshift range.
2716. PAH features of star-forming gal. using Spitzer/IRS
ID:
ivo://CDS.VizieR/J/ApJ/884/136
Title:
PAH features of star-forming gal. using Spitzer/IRS
Short Name:
J/ApJ/884/136
Date:
21 Oct 2021
Publisher:
CDS
Description:
Polycyclic aromatic hydrocarbon (PAH) emission has long been proposed to be a potential star formation rate indicator, as it arises from the photodissociation region bordering the Stromgren sphere of young, massive stars. We apply a recently developed technique of mid-infrared spectral decomposition to obtain a uniform set of PAH measurements from Spitzer low-resolution spectra of a large sample of star-forming galaxies spanning a wide range in stellar mass (M_*_~10^6^-10^11.4^M_{sun}_) and star formation rate (~0.1-2000M_{sun}_/yr). High-resolution spectra are also analyzed to measure [NeII]12.8{mu}m and [NeIII]15.6{mu}m, which effectively trace the Lyman continuum. We present a new relation between PAH luminosity and star formation rate based on the [NeII] and [NeIII] lines. Calibrations are given for the integrated 5-15{mu}m PAH emission, the individual features at 6.2, 7.7, 8.6, and 11.3{mu}m, as well as several mid- infrared bandpasses sensitive to PAH. We confirm that PAH emission is suppressed in low-mass dwarf galaxies, and we discuss the possible physical origin of this effect.
2717. PAH in extragalactic star-forming complexes
ID:
ivo://CDS.VizieR/J/MNRAS/431/2006
Title:
PAH in extragalactic star-forming complexes
Short Name:
J/MNRAS/431/2006
Date:
21 Oct 2021
Publisher:
CDS
Description:
The abundance of polycyclic aromatic hydrocarbons (PAHs) in low- and high-metallicity galaxies has been widely discussed since the time when detailed infrared data for extragalactic objects were first obtained. On the scales of entire galaxies, a smaller PAH abundance in lower metallicity galaxies is often observed. We study this relationship for star-forming regions in nearby galaxies, for a sample containing more than 200 HII complexes, using spatially resolved observations from the Herschel Space Observatory and Spitzer Space Telescope. We use a model for the dust emission to estimate the physical parameters (PAH abundance, metallicity, ultraviolet radiation field, etc.) of these complexes. The same correlation of PAH abundance with metallicity, as seen for entire galaxies, is apparently preserved at smaller scales, at least when the Kobulnicky and Kewley metallicity calibration is used. We discuss possible reasons for this correlation, noting that traces of less effective PAH formation in low-metallicity asymptotic giant branch stars should be smeared out by radial mixing in galactic discs. Effective destruction by the harder and more intensive ultraviolet field in low-metallicity environments is qualitatively consistent with our data, as the ultraviolet field intensity, derived from the infrared photometry, is indeed smaller in HII complexes with lower metallicity.
2718. PAH in galaxies at z~0.1
ID:
ivo://CDS.VizieR/J/ApJ/705/885
Title:
PAH in galaxies at z~0.1
Short Name:
J/ApJ/705/885
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the analysis of the polycyclic aromatic hydrocarbon (PAH) spectra of a sample of 92 typical star-forming galaxies at 0.03<z<0.2 observed with the Spitzer intensified Reticon spectrograph (IRS). We compare the relative strengths of PAH emission features with Sloan Digital Sky Survey optical diagnostics to probe the relationship between PAH grain properties and star formation and active galactic nuclei (AGNs) activity. Short-to-long wavelength PAH ratios, and in particular the 7.7um-to-11.3um feature ratio, are strongly correlated with the star formation diagnostics D_n_(4000) and H{alpha} equivalent width, increasing with younger stellar populations. This ratio also shows a significant difference between active and non-active galaxies, with the active galaxies exhibiting weaker 7.7um emission. A hard radiation field as measured by [OIII]/H{beta} and [NeIII]_15.6um_/[NeII]_12.8um_ effects PAH ratios differently depending on whether this field results from starburst activity or an AGN. Our results are consistent with a picture in which larger PAH molecules grow more efficiently in richer media and in which smaller PAH molecules are preferentially destroyed by the AGN.
2719. PAH luminous galaxies at z~1
ID:
ivo://CDS.VizieR/J/A+A/514/A5
Title:
PAH luminous galaxies at z~1
Short Name:
J/A+A/514/A5
Date:
21 Oct 2021
Publisher:
CDS
Description:
The NEP-deep survey, an extragalactic AKARI survey towards the north ecliptic pole (NEP), provides a comprehensive wavelength coverage from 2 to 24um using all 9 photometric bands of the infrared camera (IRC). It allows us to photometrically identify galaxies whose mid-IR emission is clearly dominated by PAHs. We propose a single-colour selection method to identify such galaxies, using two mid-IR flux ratios at 11-to-7um and 15-to-9um (PAH-to-continuum flux ratio in the rest frame), which are useful for identifying starburst galaxies at z~0.5 and 1, respectively. We perform a fitting of the spectral energy distributions (SEDs) from optical to mid-IR wavelengths, using an evolutionary starburst model with a proper treatment of radiative transfer (SBURT), in order to investigate their nature.
2720. PAH3.3um/IR luminosity for infrared galaxies
ID:
ivo://CDS.VizieR/J/PASJ/65/103
Title:
PAH3.3um/IR luminosity for infrared galaxies
Short Name:
J/PASJ/65/103
Date:
21 Oct 2021
Publisher:
CDS
Description:
For star-forming galaxies, we investigated a global relation between the polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3um, L_PAH3.3_, and the infrared (8-1000um) luminosity, L_IR_, to understand how the PAH 3.3um feature relates to star-formation activity. With AKARI, we performed near-infrared (2.5-5um) spectroscopy of 184 galaxies having L_IR_~10^8^-10^13^L_{sun}_. We classified the samples into infrared galaxies (IRGs: L_IR_<10^11^L_{sun}_), luminous infrared galaxies (LIRGs: L_IR_~10^11^-10^12^L_{sun}_ and ultra-luminous infrared galaxies (ULIRGs: L_IR_>10^12^L_{sun}_). We excluded sources likely to be contaminated by AGN activity, based on the rest-frame equivalent width of the PAH emission feature (<40nm) and the power-law index, representing the slope of continuum emission ({Gamma}>; F{nu}{prop.to}{lambda}^{Gamma}). Of these samples, 13 IRGs, 67 LIRGs, and 20 ULIRGs show the PAH emission feature at {lambda}_rest_=3.3um in their spectra. We find that the L_PAH3.3_/L_IR_ ratio considerably decreases toward the luminous end. Utilizing the mass and temperature of dust grains as well as the Br{alpha} emission for the galaxies, we discuss the cause of the relative decrease in the PAH emission with L_IR_.