- ID:
- ivo://CDS.VizieR/J/ApJ/730/19
- Title:
- IR spectra and SEDs for starbursts and AGNs
- Short Name:
- J/ApJ/730/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic results for all galaxies observed with the Spitzer Infrared Spectrograph (IRS) that also have total infrared fluxes f_IR_ measured with the Infrared Astronomical Satellite (IRAS), also using AKARI photometry when available. Infrared luminosities and spectral energy distributions (SEDs) from 8um to 160um are compared to polycyclic aromatic hydrocarbon emission from starburst galaxies or mid-infrared dust continuum from active galactic nuclei (AGNs) at rest-frame wavelengths ~8um. A total of 301 spectra are analyzed for which IRS and IRAS include the same unresolved source, as measured by the ratio f_{nu}_(IRAS 25um)/f_{nu}_(IRS 25um). Sources have 0.004<z<0.34 and 42.5<logL_IR_<46.8(erg/s) and cover the full range of starburst galaxy and AGN classifications.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/623/A135
- Title:
- IR spectral of 4 Ae/Be Herbig stars
- Short Name:
- J/A+A/623/A135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the interstellar medium, carbon (nano-)grains are a major component of interstellar dust. This solid phase is more vulnerable to processing and destruction than its silicate counterpart. It exhibits a complex, size-dependent evolution that is due to interactions within different radiative and dynamical environments. Infrared signatures of these carbon nano-grains are seen in a large number of discs around Herbig HAeBe stars. We probe the composition and evolution of carbon nano-grains at the surface of (pre-)transitional proto-planetary discs around Herbig stars. We present spatially resolved infrared emission spectra obtained with the Nasmyth Adaptive Optics System (NAOS) Near-Infrared Imager and Spectrograph (CONICA) at the Very Large Telescope (VLT) in the 3-4 microns range with a spatial resolution of 0.1-arcsec, which allowed us to trace aromatic, olefinic, and aliphatic bands that are attributed to sub-nanometer hydrocarbon grains. We applied a Gaussian fitting to analyse the observed spectral signatures. Finally, we propose an interpretation in the framework of theThe Heterogeneous dust Evolution Model of Interstellar Solids (THEMIS). We show the presence of several spatially extended spectral features that are related to aromatic and aliphatic hydrocarbon material in discs around Herbig stars, from 10 to 50-100au, and even in inner gaps that are devoid of large grains. The correlation and constant intensity ratios between aliphatic and aromatic CH stretching bands suggests a common nature of the carriers. Given their expected high destruction rates through UV photons, our observations suggest that they are continuously replenished at the disc surfaces.
- ID:
- ivo://CDS.VizieR/J/A+A/405/531
- Title:
- IR spectra of ISOGAL sources in Galactic Bulge
- Short Name:
- J/A+A/405/531
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we present near-IR spectra (HK-band) of a sample of 107 sources with mid-IR excesses at 7 and 15{mu}m detected during the ISOGAL survey. Making use of the DENIS interstellar extinction map from Schultheis et al. (1999, Cat. <J/A+A/349/L69>) we derive luminosities and find that the Mbol vs. ^12^CO and Mbol vs. H_2_O diagrams are powerful tools for identifying supergiants, AGB stars, giants and young stellar objects. The majority of our sample are AGB stars (~80%) while we find four good supergiant candidates, nine young stellar objects and 12 RGB candidates. We have used the most recent K_0_-[15] relation by Jeong et al. (2002, in Mass-losing Pulsating tars and their Circumstellar Matter, ed. Y. Nakasa, M. Honma, & M. Sekiin) based on recent theoretical modeling of dust formation of AGB stars to determine mass-loss rates. The mass-loss rates of the supergiants are comparable with those in the solar neighbourhood while the long-period Variables cover a mass-loss range from -5<log(dM/dt)<-7. The red giant candidates lie at the lower end of the mass-loss rate range between -6.5<log(dM/dt)<-9. We used the equivalent width of the CO bandhead at 2.3 mum, the NaI doublet and the CaI triplet to estimate metallicities using the relation by Ramirez et al. (2000ApJ...537..205R). The metallicity distribution of the ISOGAL objects shows a mean [Fe/H]~-0.25dex with a dispersion of +/-0.40dex which is in agreement with the values of Ramirez et al. (2000ApJ...537..205R) for Galactic Bulge fields between b=-4{deg} and b=-1.3{deg}. A comparison with the solar neighbourhood sample of Lancon & Wood (2000, Cat. <J/A+AS/146/217>) shows that our sample is ~0.5dex more metal-rich on average.
- ID:
- ivo://CDS.VizieR/J/ApJ/670/1115
- Title:
- IRS spectra at 38 positions in Galactic center
- Short Name:
- J/ApJ/670/1115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Spitzer IRS spectra (R~600, 10-38um) of 38 positions in the Galactic center, all at the same Galactic longitude and spanning +/-0.3{deg} in latitude. Our positions include the Arches Cluster, the Arched Filaments, regions near the Quintuplet Cluster, the "Bubble" lying along the same line of sight as the molecular cloud G0.11-0.11, and the diffuse interstellar gas along the line of sight at higher Galactic latitudes.
- ID:
- ivo://CDS.VizieR/J/A+A/397/177
- Title:
- IR star clusters and stellar groups catalog
- Short Name:
- J/A+A/397/177
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compiled a catalogue of infrared star clusters in the Galaxy, which are most of them embedded. It condenses the growing literature information. We also include in the sample infrared stellar groups which are less dense than star clusters, such as those embedded in the dark clouds Taurus-Auriga and Chamaleon I. We provide galactic and equatorial coordinates, angular dimensions, different designations and related objects such as nebulae. A total of 189 infrared clusters and 87 embedded stellar groups are included. A fraction of 25% of the embedded clusters are projected close to each other in pair or triplet systems, indicating that multiplicity plays an important role in star cluster formation.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/39
- Title:
- IR survey of brightest cluster galaxies I.
- Short Name:
- J/ApJS/176/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies (BCGs) with optical line emission. These galaxies are located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that about half of these sources have a sign of excess infrared emission; 22 objects out of 62 are detected at 70um, 18 have 8/5.8um flux ratios above 1.0 and 28 have 24/8um flux ratios above 1.0. Altogether 35 of 62 objects in our survey exhibit at least one of these signs of infrared excess. Four galaxies with infrared excesses have a 4.5/3.6um flux ratio indicating the presence of hot dust, and/or an unresolved nucleus at 8um. Three of these have high measured [OIII](5007{AA})/H{beta} flux ratios suggesting that these four, Abell 1068, Abell 2146, Zwicky 2089, and R0821+07, host dusty active galactic nuclei (AGNs). Nine objects (including the four hosting dusty AGNs) have infrared luminosities greater than 10^11^L_{sun}_ and so can be classified as luminous infrared galaxies (LIRGs). Excluding the four systems hosting dusty AGNs, the excess mid-infrared emission in the remaining brightest cluster galaxies is likely related to star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/392/239
- Title:
- IR survey of outflows in Orion A
- Short Name:
- J/A+A/392/239
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have made an unbiased imaging survey of a 1.2 square degree area in the Orion A giant molecular cloud searching for molecular hydrogen emission line features seen in the v=1-0 S(1) line at a wavelength of 2.12{mu}m originating in shocks in outflows from young stellar objects. This survey provides for the first time an unbiased census of outflows over a significant portion of a giant molecular cloud, and yields a sample of outflows free from selection effects and with all objects located at roughly the same, well-known distance. In this paper, we present the data gathered in the course of the survey, provide a comprehensive list of all molecular hydrogen emission features found, and give a list of the 76 candidate outflows identified in the data set.
- ID:
- ivo://CDS.VizieR/J/ApJ/606/929
- Title:
- IR to mm observations of IRAS 18317-0757
- Short Name:
- J/ApJ/606/929
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution, multiwavelength-continuum, and molecular-line images of the massive star forming region IRAS 18317-0757. The global infrared through millimeter spectral energy distribution can be approximated by a two-temperature model (25 and 63K) with a total luminosity of approximately log(L/L_{sun}_)=5.2. Previous submillimeter imaging resolved this region into a cluster of five dust cores, one of which is associated with the ultracompact HII region G23.955+0.150, and another with a water maser. In our new 2.7mm continuum image obtained with BIMA, only the UCHII region is detected, with total flux and morphology in good agreement with the free-free emission in the VLA centimeter-wave maps. For the other four objects, the nondetections at 2.7mm and in the MSX mid-infrared bands are consistent with cool dust emission with a temperature of 13-40K and a luminosity of 1000-40000L_{sun}_. By combining single-dish and interferometric data, we have identified over two dozen virialized C^18^O cores in this region that contain ~40% of the total molecular gas mass present.
- ID:
- ivo://CDS.VizieR/J/ApJ/826/209
- Title:
- IRX-{beta} relation of HII regions in NGC628
- Short Name:
- J/ApJ/826/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It has been found that the infrared-to-ultraviolet luminosity ratio (IRX) and ultraviolet spectral slope ({beta}) have a tight correlation in starburst galaxies, while in normal galaxies the relation is deviated and has a much larger scatter. Star formation regions are much simpler in both morphology and physical properties than galaxies, so their photometric and spectroscopic properties are more easily and accurately determined. We have used the integral field spectroscopy and multiband photometric images to study the IRX-{beta} relation of HII regions in a nearby galaxy, NGC 628. There are obvious correlations between the D_n_ (4000), stellar population age, star formation rate, especially H{alpha} equivalent width EW(H{alpha}), and deviation distance d_p_ from the starburst IRX-{beta} relation. However, there is little correlation between the Balmer decrement, metallicity, and d_p_. It is much more complicated than expected, so that we cannot introduce a single second parameter to describe the scatter and deviation of the HII region IRX-{beta} relation.
- ID:
- ivo://CDS.VizieR/J/A+A/401/613
- Title:
- ISOCAM-CVF spectroscopy of YSO environment
- Short Name:
- J/A+A/401/613
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a mid-infrared (5-16.5{mu}m) imaging spectroscopy survey of Young Stellar Objects (YSOs) and their surrounding environment in four low-mass star formation regions: R CrA, {rho} Ophiuchi, Serpens and Chamaeleon I. This survey was performed using ISOCAM and its Circular Variable Filters (CVF) and observed 42 YSO candidates: we were able to obtain complete 5-16.5{mu}m spectra for 40 of these with a spectral resolving power of {lambda}/{Delta}{lambda}~40.