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2231. Mid-infrared population of ELAIS-S1 sample
ID:
ivo://CDS.VizieR/J/AJ/127/3075
Title:
Mid-infrared population of ELAIS-S1 sample
Short Name:
J/AJ/127/3075
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a multiwavelength catalog (15{mu}m, R-band, K-band, and 1.4GHz flux) plus spectroscopic identifications for 406 15{mu}m sources detected in the European Large Area ISO Survey (ELAIS) region S1, over the flux density range 0.5<S15{mu}m<150mJy. Three hundred thirty-two (~82%) sources are optically identified down to R~23.0. Spectra or bona fide stellar identifications are obtained for 290 objects (~88% of the optically identified sources). The areal coverage, mid-infrared (MIR) and optical completeness of the sample are discussed in order to allow statistical and evolutionary analyses.
2232. Mid-infrared properties of luminous IR galaxies
ID:
ivo://CDS.VizieR/J/A+A/451/57
Title:
Mid-infrared properties of luminous IR galaxies
Short Name:
J/A+A/451/57
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present evidence that the mid infrared (MIR, rest frame 5-30{mu}m) is a good tracer of the total infrared luminosity, L(IR)(=L[8-1000{mu}m]), and star formation rate (SFR), of galaxies up to z~1.3. We use deep MIR images from the Infrared Space Observatory (ISO) and the Spitzer Space Telescope in the Northern field of the Great Observatories Origins Deep Survey (GOODS-N) together with VLA radio data to compute three independant estimates of L(IR). The L(IR,MIR) derived from the observed 15 and/or 24{mu}m flux densities using a library of template SEDs, and L(IR,radio), derived from the radio (1.4 and/or 8.5GHz) using the radio-far infrared correlation, agree with a 1-sigma dispersion of 40%. We use the k-correction as a tool to probe different parts of the MIR spectral energy distribution (SED) of galaxies as a function of their redshift and find that on average distant galaxies present MIR SEDs very similar to local ones.
2233. Mid-infrared spectroscopy of LINERs
ID:
ivo://CDS.VizieR/J/A+A/414/825
Title:
Mid-infrared spectroscopy of LINERs
Short Name:
J/A+A/414/825
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a comprehensive comparative high resolution mid-IR spectroscopic and X-ray imaging investigation of LINERs using archival observations from the ISO-SWS and the Chandra Advanced CCD Imaging Spectrometer. Although the sample is heterogeneous and incomplete, this is the first comprehensive study of the mid-infrared fine structure line emission of LINERs.
2234. Mid-infrared-X-ray correlation for local AGNs
ID:
ivo://CDS.VizieR/J/MNRAS/454/766
Title:
Mid-infrared-X-ray correlation for local AGNs
Short Name:
J/MNRAS/454/766
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an updated mid-infrared (MIR) versus X-ray correlation for the local active galactic nuclei (AGN) population based on the high angular resolution 12 and 18{mu}m continuum fluxes from the AGN subarcsecond MIR atlas and 2-10 keV and 14-195 keV data collected from the literature. We isolate a sample of 152 objects with reliable AGN nature and multi-epoch X-ray data and minimal MIR contribution from star formation. Although the sample is not homogeneous or complete, we show that our results are unlikely to be affected by significant biases. The MIR-X-ray correlation is nearly linear and within a factor of 2 independent of the AGN type and the wavebands used. The observed scatter is <0.4 dex. A possible flattening of the correlation slope at the highest luminosities probed (~10^45^ erg/s) towards low MIR luminosities for a given X-ray luminosity is indicated but not significant. Unobscured objects have, on average, an MIR-X-ray ratio that is only <=0.15 dex higher than that of obscured objects. Objects with intermediate X-ray column densities (22<logN_H_<23) actually show the highest MIR-X-ray ratio on average. Radio-loud objects show a higher mean MIR-X-ray ratio at low luminosities while the ratio is lower than average at high luminosities. This may be explained by synchrotron emission from the jet contributing to the MIR at low luminosities and additional X-ray emission at high luminosities. True Seyfert 2 candidates do not show any deviation from the general behaviour suggesting that they possess a dusty obscurer as in other AGN. Double AGN also do not deviate. Finally, we show that the MIR-X-ray correlation can be used to investigate the AGN nature of uncertain objects. Specifically, we give equations that allow us to determine the intrinsic 2-10 keV luminosities and column densities for objects with complex X-ray properties to within 0.34 dex. These techniques are applied to the uncertain objects of the remaining AGN MIR atlas, demonstrating the usefulness of the MIR-X-ray correlation as an empirical tool.
2235. Mid-IR emission lines in AGNs
ID:
ivo://CDS.VizieR/J/ApJ/725/2270
Title:
Mid-IR emission lines in AGNs
Short Name:
J/ApJ/725/2270
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used Spitzer/Infrared Spectrograph spectroscopic data on 426 galaxies including quasars, Seyferts, LINERs, and HII galaxies to investigate the relationship among the mid-IR emission lines. There is a tight linear correlation between the [NeV]14.3um and 24.3um (97.1eV) and the [OIV]25.9um (54.9eV) high-ionization emission lines. The correlation also holds for these high-ionization emission lines and the [NeIII]15.56um (41eV) emission line, although only for active galaxies. We used these correlations to calculate the [NeIII] excess due to star formation in Seyfert galaxies. We also estimated the [OIV] luminosity due to star formation in active galaxies and determined that it dominates the [OIV] emission only if the contribution of the active nucleus to the total luminosity is below 5%. We find that the active galactic nucleus dominates the [OIV] emission in most Seyfert galaxies, whereas star formation adequately explains the observed [OIV] emission in optically classified HII galaxies. Finally, we computed photoionization models to determine the physical conditions of the narrow-line region where these high-ionization lines originate. The estimated ionization parameter range is -2.8<logU<-2.5 and the total hydrogen column density range is 20<logn_H_(cm^-2^)<21.
2236. Mid-IR galaxies in Virgo cluster. III.
ID:
ivo://CDS.VizieR/J/A+A/406/867
Title:
Mid-IR galaxies in Virgo cluster. III.
Short Name:
J/A+A/406/867
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present ISOCAM imaging data at 6.75 and 15{mu}m for 145 galaxies in the Virgo cluster and in the Coma/A1367 supercluster. Of these, 99 form a complete, optically-selected, volume-limited sample including galaxies in the core and in the periphery of the Virgo cluster, suitable for statistical analysis. 34 of the Virgo galaxies were resolved by ISOCAM: for these objects we present mid-IR images, radial light and colour profiles, as well as effective and isophotal radii, surface brightness and light concentration indices.
2237. Mid-IR galaxy morphology from S^4^G
ID:
ivo://CDS.VizieR/J/ApJS/190/147
Title:
Mid-IR galaxy morphology from S^4^G
Short Name:
J/ApJS/190/147
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spitzer Space Telescope Infrared Array Camera imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6um band, which is the best Spitzer waveband for galactic stellar mass morphology owing to its depth and its reddening-free sensitivity mainly to older stars. For this purpose, we have prepared classification images for 207 galaxies from the Spitzer archive, most of which are formally part of the Spitzer Survey of Stellar Structure in Galaxies (S^4^G), a Spitzer post-cryogenic ("warm") mission Exploration Science Legacy Program survey of 2331 galaxies closer than 40Mpc. For the purposes of morphology, the galaxies are interpreted as if the images are blue light, the historical waveband for classical galaxy classification studies. We find that 3.6um classifications are well correlated with blue-light classifications, to the point where the essential features of many galaxies look very similar in the two very different wavelength regimes. We present an atlas of all of the 207 galaxies analyzed here and bring attention to special features or galaxy types, such as nuclear rings, pseudobulges, flocculent spiral galaxies, I0 galaxies, double-stage and double-variety galaxies, and outer rings, that are particularly distinctive in the mid-IR.
2238. Mid-IR indicators of SF and AGN in galaxies
ID:
ivo://CDS.VizieR/J/ApJ/719/1191
Title:
Mid-IR indicators of SF and AGN in galaxies
Short Name:
J/ApJ/719/1191
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the use of mid-infrared (MIR) polycyclic aromatic hydrocarbon (PAH) bands, the continuum, and emission lines as probes of star formation (SF) and active galactic nucleus (AGN) activity in a sample of 100 "normal" and local (z~0.1) emission-line galaxies. The MIR spectra were obtained with the Spitzer Space Telescope Infrared Spectrograph as part of the Spitzer-SDSS-GALEX Spectroscopic Survey (SSGSS), which includes multi-wavelength photometry from the ultraviolet to the far-infrared and optical spectroscopy. The continuum and features were extracted using PAHFIT, a decomposition code which we find to yield PAH equivalent widths (EWs) up to ~30 times larger than the commonly used spline methods. Despite the lack of extreme objects in our sample (such as strong AGNs, low-metallicity galaxies, or ULIRGs), we find significant variations in PAH, continuum, and emission-line properties, and systematic trends between these MIR properties and optically derived physical properties, such as age, metallicity, and radiation field hardness. We revisit the diagnostic diagram relating PAH EWs and [NeII]12.8um/[OIV]25.9um line ratios and find it to be in much better agreement with the standard optical SF/AGN classification than when spline decompositions are used, while also potentially revealing obscured AGNs.
2239. Mid-IR observations in the extended Groth strip
ID:
ivo://CDS.VizieR/J/ApJ/642/126
Title:
Mid-IR observations in the extended Groth strip
Short Name:
J/ApJ/642/126
Date:
21 Oct 2021
Publisher:
CDS
Description:
A sample of about 150 AGNs was selected from observations of Chandra and XMM X-ray observatories in a 300arcmin^2^ region of the extended Groth strip (EGS), and observed by the IRAC and MIPS instruments of the Spitzer IR telescope. About 68-80% of these sources were detected by Spitzer, and they show a wide range of mid-infrared properties. The IRAC SED type does not directly correspond to X-ray spectral type (hard/soft). The mid-IR properties of X-ray-detected Lyman break, radio, submillimeter, and optically faint sources vary widely, and for the most part are not distinct from those of the general X-ray/IR source population. X-ray sources emit 6-11% of the integrated mid-IR light, making them significant contributors to the cosmic infrared background.
2240. Mid-IR properties of GOALS nearby LIRGs
ID:
ivo://CDS.VizieR/J/ApJS/206/1
Title:
Mid-IR properties of GOALS nearby LIRGs
Short Name:
J/ApJS/206/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Great Observatories All-Sky LIRG Survey (GOALS, Armus et al. 2009PASP..121..559A) is a comprehensive, multiwavelength study of luminous infrared galaxies (LIRGs) in the local universe. Here we present low resolution Spitzer Infrared Spectrograph spectra covering 5-38um and provide a basic analysis of the mid-IR spectral properties observed for nearby LIRGs. In a companion paper, we discuss detailed fits to the spectra and compare the LIRGs to other classes of galaxies. The GOALS sample of 244 nuclei in 180 luminous (10^11^<=L_IR_/L_{sun}_<10^12^) and 22 ultraluminous (L_IR_/L_{sun}_>=10^12^) IR galaxies represents a complete subset of the IRAS Revised Bright Galaxy Sample (Sanders, 2003, Cat. J/AJ/126/1607) and covers a range of merger stages, morphologies, and spectral types. The majority (>60%) of the GOALS LIRGs have high 6.2um polycyclic aromatic hydrocarbon (PAH) equivalent widths (EQW_6.2um_>0.4um) and low levels of silicate absorption (s_9.7um_>-1.0).