- ID:
- ivo://CDS.VizieR/J/A+A/659/A77
- Title:
- FEEDBACK from the NGC7538 HII region
- Short Name:
- J/A+A/659/A77
- Date:
- 14 Mar 2022 07:43:25
- Publisher:
- CDS
- Description:
- The interaction of expanding HII regions with their environmental cloud is one of the central questions driving the SOFIA legacy program FEEDBACK. We want to understand the interaction of the prototypical NGC7538 HII region with the neighboring molecular cloud hosting several active star-forming regions. Using the Stratospheric Observatory for Infrared Astronomy (SOFIA), we mapped an area of ~210'^2^ (~125pc^2^) around NGC7538 in the velocity-resolved ionized carbon fine-structure line [CII] at 1.9THz (158um). Complementary observed atomic carbon [CI] at 492GHz and high-J CO(8-7) data, as well as the archival near- and far-infrared, cm continuum, CO(3-2), and HI data are folded into the analysis. The ionized carbon [CII] data reveal rich morphological and kinematic structures. While the overall morphology follows the general ionized gas that is also visible in the radio continuum emission, the channel maps show multiple bubble-like structures with sizes on the order of ~80-100'' (~1.0-1.28pc). While at least one of them may be an individual feedback bubble driven by the main exciting sources of the NGC7538 HII region (the O3 and O9 stars IRS6 and IRS5), the other bubble-like morphologies may also be due to the intrinsically porous structure of the HII region. An analysis of the expansion velocities around 10km/s indicates that thermal expansion is not sufficient but that wind-driving from the central O-stars is required. The region exhibits a general velocity gradient across, but we also identify several individual velocity components. The most blue-shifted [CII] component has barely any molecular or atomic counterparts. At the interface to the molecular cloud, we find a typical photon-dominated region (PDR) with a bar-shape. Ionized C+, atomic C0 and molecular carbon CO show a layered structure in this PDR. The carbon in the PDR is dominated by its ionized C+ form with atomic C0 and molecular CO masses of ~0.45+/-0.1M_{sun}_ and ~1.2+/-0.1M_{sun}_, respectively, compared to the ionized carbon C+ in the range of 3.6-9.7M_{sun}_. This bar-shaped PDR exhibits a velocity-gradient across, indicating motions along the line of sight toward the observer. Even if it is shown to be dominated by two nearby exciting sources (IRS6 and IRS5), the NGC7538 HII region exhibits a diverse set of substructures that interact with each other as well as with the adjacent cloud. Compared to other recent [CII] observations of HII regions (e.g., Orion Veil, RCW120, RCW49), the bubble-shape morphologies revealed in [CII] emission that are indicative of expanding shells are recurring structures of PDRs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/248/23
- Title:
- 4FGL sources with IR/Rad associations
- Short Name:
- J/ApJS/248/23
- Date:
- 09 Nov 2021 09:30:22
- Publisher:
- CDS
- Description:
- Associating {gamma}-ray sources to their low-energy counterparts is one of the major challenges of modern {gamma}-ray astronomy. In the context of the Fourth Fermi Large Area Telescope Source Catalog (4FGL), the associations rely mainly on parameters such as apparent magnitude, integrated flux, and angular separation between the {gamma}-ray source and its low-energy candidate counterpart. In this work, we propose a new use of the likelihood ratio (LR) and a complementary supervised learning technique to associate {gamma}-ray blazars in 4FGL, based only on spectral parameters such as the {gamma}-ray photon index, mid-infrared colors, and radio-loudness. In the LR approach, we crossmatch the Wide-field Infrared Survey Explorer Blazar-Like Radio-Loud Sources catalog with 4FGL and compare the resulting candidate counterparts with the sources listed in the {gamma}-ray blazar locus to compute an association probability (AP) for 1138 counterparts. In the supervised learning approach, we train a random forest algorithm with 869 high-confidence blazar associations and 711 fake associations and then compute an AP for 1311 candidate counterparts. A list with all 4FGL blazar candidates of uncertain type associated by our method is provided to guide future optical spectroscopic follow-up observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/397
- Title:
- Final analysis of ELAIS 15-{mu}m
- Short Name:
- J/MNRAS/358/397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final analysis of the European Large Area Infrared Space Observatory (ISO) Survey (ELAIS) 15-{mu}m observations, carried out with the ISO Camera (ISOCAM) instrument on board the ISO. The data-reduction method, known as the Lari Method, is based on a mathematical model of the behaviour of the detector and was specifically designed for the detection of faint sources in ISOCAM/ISO Photopolarimeter (ISOPHOT) data. The method is fully interactive and leads to very reliable and complete source lists. The resulting catalogue includes 1923 sources detected with signal-to-noise ratio of >5 in the 0.5-100mJy flux range and over an area of 10.85deg^2^ split into four fields, making it the largest non-serendipitous extragalactic source catalogue obtained to date from the ISO data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/432/2182
- Title:
- FIR bright sources of M83
- Short Name:
- J/MNRAS/432/2182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate star formation and dust heating in the compact far-infrared (FIR) bright sources detected in the Herschel maps of M83. We use the source extraction code GETSOURCES to detect and extract sources in the FIR, as well as their photometry in the mid-infrared and H{alpha}. By performing infrared spectral energy distribution fitting and applying an H{alpha}-based star formation rate (SFR) calibration, we derive the dust masses and temperatures, SFRs, gas masses and star formation efficiencies (SFEs). The detected sources lie exclusively on the spiral arms and represent giant molecular associations, with gas masses and sizes of 106-108M{sun} and 200-300pc, respectively. The inferred parameters show little to no radial dependence and there is only a weak correlation between the SFRs and gas masses, which suggests that more massive clouds are less efficient at forming stars. Dust heating is mainly due to local star formation. However, although the sources are not optically thick, the total intrinsic young stellar population luminosity can almost completely account for the dust luminosity. This suggests that other radiation sources also contribute to the dust heating and approximately compensate for the unabsorbed fraction of UV light.
- ID:
- ivo://CDS.VizieR/J/ApJ/840/21
- Title:
- FIR data of IR-bright dust-obscured galaxies (DOGs)
- Short Name:
- J/ApJ/840/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the star-forming activity of a sample of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme red color in the optical and IR regime, (i-[22])_AB_>7.0. Combining an IR-bright DOG sample with the flux at 22{mu}m>3.8mJy discovered by Toba & Nagao (2016ApJ...820...46T) with the IRAS faint source catalog version 2 and AKARI far-IR (FIR) all-sky survey bright source catalog version 2, we selected 109 DOGs with FIR data. For a subsample of seven IR-bright DOGs with spectroscopic redshifts (0.07<z<1.0) that were obtained from the literature, we estimated their IR luminosity, star formation rate (SFR), and stellar mass based on the spectral energy distribution fitting. We found that (1) the WISE 22{mu}m luminosity at the observed frame is a good indicator of IR luminosity for IR-bright DOGs and (2) the contribution of the active galactic nucleus to IR luminosity increases with IR luminosity. By comparing the stellar mass and SFR relation for our DOG sample and the literature, we found that most of the IR-bright DOGs lie significantly above the main sequence of star-forming galaxies at similar redshift, indicating that the majority of IRAS- or AKARI-detected IR-bright DOGs are starburst galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/682/985
- Title:
- FIREWORKS photometry of GOODS CDF-S
- Short Name:
- J/ApJ/682/985
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Ks-selected catalog, dubbed FIREWORKS, for the Chandra Deep Field-South (CDF-S) containing photometry in the U_38_, B_435_, B, V, V_606_, R, i_775_, I, z_850_, J, H, Ks, [3.6um], [4.5um], [5.8um], [8.0um], and MIPS [24um] bands. The imaging has a typical K^tot^_s,AB_ limit of 24.3mag (5{sigma}) and coverage over 113arcmin^2^ in all bands and 138arcmin^2^ in all bands but H. We cross-correlate our catalog with the 1Ms X-ray catalog by Giacconi et al. (2002, Cat. J/ApJS/139/369) and with all available spectroscopic redshifts to date. We find and explain systematic differences in a comparison with the "z_850_+Ks"-selected GOODS-MUSIC catalog (Cat. J/A+A/449/951) that covers ~90% of the field. We exploit the U_38_-to-24um photometry to determine which Ks-selected galaxies at 1.5<z<2.5 have the brightest total IR luminosities and which galaxies contribute most to the integrated total IR emission. The answer to both questions is that red galaxies are dominating in the IR. This is true no matter whether color is defined in the rest-frame UV, optical, or optical-near-IR. We do find, however, that among the reddest galaxies in the rest-frame optical, there is a population of sources with only little mid-IR emission, suggesting a quiescent nature.
- ID:
- ivo://CDS.VizieR/III/246
- Title:
- First Byurakan Survey Late Type Stars catalog
- Short Name:
- III/246
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The First Byurakan Survey (FBS), also known as the Markarian survey, covers about 17000 sq. deg. It has been used by Markarian and his collaborators to search for UV excess galaxies (see Cat. VII/172), by Abrahamyan and his collaborators to search for late type stars and UV excess or emission line point sources (stars and starlike objects). The identification, classification, and investigation of late type stars and blue stellar objects constitutes the second part of the First Byurakan Survey and is a natural continuation of it. For this second program, at the present time, a catalogue of 1103 blue objects has been built (see Cat. II/223). In a series of 14 papers, referenced in the "References" section below, have been published lists of 1000 late M type and carbon stars, selected on the FBS plates. We have revised and updated this 14 lists with the new data from recently published optical and infrared catalogs to give access to all available data. As a result, the catalog of the First Byurakan Survey (FBS) Late Type Stars, was compiled. In this catalogue are presented high accurate coordinates, proper motions, spectral, photometric and infrared dates about of 995 FBS late M type and carbon stars. Are given cross-identifications of FBS late type stars with their counterparts from the most popular catalogs (2MASS, USNO-B1, NOMAD, UCAC2, GCVS4.2, NSVS, ASAS, IRAS PS and IRAS FS). On the base of 2MASS (J-K) color indices were determined a luminosity classes for 988 of them. For the 55 stars were determined a spectral classes, and for the another 129 were determined a spectral subclasses on the base of DFBS (http://byurakan.phys.uniroma1.it/) These data were not presented in original lists.
- ID:
- ivo://CDS.VizieR/J/MNRAS/489/2030
- Title:
- First Byurakan Survey of Late-Type Stars - v2
- Short Name:
- J/MNRAS/489/2030
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 18 lists of the First Byurakan Survey of Late-Type Stars (FBS LTS) were published between 1990 and 2016. The stars were found on FBS low-dispersion spectroscopic plates. A systematic search and selection were carried out on a surface of ~16000deg^2^ on almost the whole area of the FBS. As a result, the "Revised and Updated Catalogue of the First Byurakan Survey of Late-Type Stars" was generated (FBS LTS v1; see Cat. III/266 -- 1045 objects). We present the second version of the catalogue of FBS LTS with new data (FBS LTS v2), comprising 1471 objects. It is a homogeneous and complete data base for high-Galactic-latitude, late-type stars, including M and C types. Since 2007, all FBS low-resolution spectral plates have been digitized. All digitized FBS (DFBS) spectral plates have been analysed with FITSVIEW and SAO IMAGE DS9, and numerous relatively faint LTSs have been discovered. We have performed cross-correlations with DFBS, USNO-B1.0, 2MASS, AllWISE, IRAS PSC/FSC, AKARI, ROSAT BSC/FSC, GCVS, SDSS and added updated SIMBAD data. For numerous new detected objects, we present accurate DSS2 positions, approximate spectral subtypes refined from the DFBS low-dispersion spectra, luminosity classes estimated from 2MASS colours, and available proper motions for 1471 FBS LTSs. The Revised and Updated Catalogue v2 lists a large number of completely new objects, which promises to extend very significantly the census of M giants, faint N-type asymptotic giant branch carbon stars, CH-type carbon giants at high Galactic latitudes, and M dwarfs in the Solar vicinity up to 16.0-17.0mag in the visual. Some important data from Gaia DR2 and supplementary spectra from the Byurakan Astrophysical Observatory 2.6m and LAMOST telescopes are presented.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/133
- Title:
- First DENIS I-band extragalactic catalog
- Short Name:
- J/A+AS/135/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- REDCAT is the release of the provisional extragalactic catalogue constructed from the "Deep Near Infrared Southern Sky Survey" (DENIS). This catalogue contains 20260 galaxies with coordinates and I-band photometry (magnitude, diameter, axis ratio, position angle and a parameter related to the morphological type). In this new version photometric parameters are homogeneized to I-band measurements by Mathewson and Ford (1997, Cat. <J/ApJS/107/97>). Additional information on galaxies cross-identified with known objects can be obtained through the LEDA database at: http://www-obs.univ-lyon1.fr/leda/leda-consult.html This catalogue is the result of a tremendous work done along the chain Chile-Paris-Lyon. Many people are involved in this programm conducted by the P.I. N. Epchtein. We will not take the risk to mention them all. Their names will appear in forthcoming papers. The distribution on the sky is made of strips of 30 degrees in declination (180 frames per strip) south of +02{deg}. If you are satisfied with this catalogue, try to push the Community to support the DENIS project. Your suggestions are welcome for any improvement of this first release.
- ID:
- ivo://CDS.VizieR/J/ApJ/607/60
- Title:
- FIRST-2MASS faint sources
- Short Name:
- J/ApJ/607/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have constructed a sample of bright near-infrared sources that are detected at radio wavelengths but undetected on the first-generation Palomar Observatory Sky Survey (POSSI) plates in order to search for a population of dust-obscured quasars. Optical and infrared spectroscopic follow-up of the sample has led to the discovery of 17 heavily reddened quasars (B-K>6.5), 14 of which are reported here for the first time. This has allowed us to define a region in the R-K, J-K color plane in which 50% of the radio-selected objects are highly reddened quasars. We compare the surface density of this previously overlooked population to that of ultraviolet-excess radio-selected quasars, finding that they make up ~20% of the total quasar population for K<~15.5.