- ID:
- ivo://CDS.VizieR/J/A+A/560/A76
- Title:
- Catalog of stellar clusters in the inner Galaxy
- Short Name:
- J/A+A/560/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stars are born within dense clumps of giant molecular clouds, and constitute young stellar agglomerates known as embedded clusters, which only evolve into bound open clusters under special conditions. We statistically study all embedded clusters (ECs) and open clusters (OCs) known so far in the inner Galaxy, in particular investigating their interaction with the surrounding molecular environment and the differences in their evolution.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/389/678
- Title:
- Catalogue of extended objects in Magellanic Clouds
- Short Name:
- J/MNRAS/389/678
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We update the Small Magellanic Cloud (SMC), Bridge and Large Magellanic Cloud (LMC) catalogues of extended objects that were constructed by members of our group from 1995 to 2000. In addition to the rich subsequent literature for the previous classes, we now also include HI shells and supershells. A total of 9305 objects were cross-identified, while our previous catalogues amounted to 7900 entries, an increase of ~12 per cent. We present the results in subcatalogues containing 1445 emission nebulae, 3740 star clusters, 3326 associations and 794 HI shells and supershells. Angular and apparent size distributions of the extended objects are analysed. We conclude that the objects, in general, appear to respond to tidal effects arising from the LMC, SMC and Bridge. Number-density profiles extracted along directions parallel and perpendicular to the LMC bar, can be described by two exponential-discs. A single exponential-disc fits the equivalent SMC profiles. Interestingly, when angular-averaged number-densities of most of the extended objects are considered, the profiles of both Clouds do not follow an exponential-disc. Rather, they are best described by a tidally truncated, core/halo profile, despite the fact that the Clouds are clearly disturbed discs. On the other hand, the older star clusters taken isolately, distribute as an exponential disc. The present catalogue is an important tool for the unambiguous identification of previous objects in current CCD surveys and to establish new findings.
- ID:
- ivo://CDS.VizieR/VII/20
- Title:
- Catalogue of HII Regions
- Short Name:
- VII/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue describes the position, maximum angular diameters, classifications according to form, structure and brightness, and the number of associated stars. The acronym used in the literature to designate objects from this catalogue is Sh 2 (e.g. Sh 2-1 for the first HII region of the catalogue)
- ID:
- ivo://CDS.VizieR/J/ApJ/921/91
- Title:
- Catastrophic cooling in superwinds. II.
- Short Name:
- J/ApJ/921/91
- Date:
- 15 Nov 2021
- Publisher:
- CDS
- Description:
- Superwinds and superbubbles driven by mechanical feedback from super star clusters (SSCs) are common features in many star-forming galaxies. While the adiabatic fluid model can well describe the dynamics of superwinds, several observations of starburst galaxies revealed the presence of compact regions with suppressed superwinds and strongly radiative cooling, i.e., catastrophic cooling. In the present study, we employ the non-equilibrium atomic chemistry and cooling package MAIHEM, built on the FLASH hydrodynamics code, to generate a grid of models investigating the dependence of cooling modes on the metallicity, SSC outflow parameters, and ambient density. While gas metallicity plays a substantial role, catastrophic cooling is more sensitive to high mass-loading and reduced kinetic heating efficiency. Our hydrodynamic simulations indicate that the presence of a hot superbubble does not necessarily imply an adiabatic outflow, and vice versa. Using CLOUDY photoionization models, we predict UV and optical line emission for both adiabatic and catastrophic cooling outflows, for radiation-bounded and partially density-bounded models. Although the line ratios predicted by our radiation-bounded models agree well with observations of star-forming galaxies, they do not provide diagnostics that unambiguously distinguish the parameter space of catastrophically cooling flows. Comparison with observations suggests the possibility of minor density bounding, non-equilibrium ionization, and/or observational bias toward the central outflow regions.
- ID:
- ivo://CDS.VizieR/J/AJ/119/1214
- Title:
- Census of star clusters in the SMC
- Short Name:
- J/AJ/119/1214
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Surveys using CCD detectors are retrieving bright and faint catalogued clusters and revealing new ones in the Magellanic Clouds. This paper discusses the contribution of the OGLE Survey to the overall census of star clusters in the Small Magellanic Cloud (SMC). A detailed cross-identification indicates that the new objects in the SMC OGLE catalog are 46. The increase in the number of catalogued clusters is {~}7%, the total sample being {~}700. This updated census includes embedded clusters in H II regions and a density range attaining loose systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/607/904
- Title:
- Chandra obs. of Trifid nebula
- Short Name:
- J/ApJ/607/904
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Trifid Nebula, a young star-forming H II region, was observed for 16hr by the ACIS-I detector on board the Chandra X-Ray Observatory. We detected 304 X-ray sources, 30% of which are hard sources and 70% of which have near-infrared counterparts.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A120
- Title:
- Chandra X-ray observation of Gum 31
- Short Name:
- J/A+A/564/A120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gum 31 is a prominent, but still rather poorly studied HII region around the stellar cluster NGC 3324 at the northwestern periphery of the Carina nebula complex. Our aim was to reveal and characterize the young stellar population in Gum 31. An X-ray survey is the only efficient way to identify young stars in this region with extremely high galactic field-star contamination that can avoid the strong biases of infrared excess selected samples of disk-bearing young stars. We used the Chandra observatory to perform a deep (70ks) X-ray observation of the Gum 31 region and detected 679 X-ray point sources. This extends and complements the X-ray survey of the central Carina nebula regions performed in the Chandra Carina Complex Project (CCCP). Using deep near-infrared images from our recent VISTA survey of the Carina nebula complex, our comprehensive Spitzer point-source catalog, and optical archive data, we identify counterparts for 75% of these X-ray sources.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/248
- Title:
- Chemical properties of red MSX sources (RMSs)
- Short Name:
- J/ApJ/833/248
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Red Midcourse Space Experiment (MSX) Sources (RMSs) are regarded as excellent candidates of massive star-forming regions. In order to characterize the chemical properties of massive star formation, we made a systematic study of 87 RMSs in the southern sky, using archival data taken from the Atacama Pathfinder Experiment Telescope Large Area Survey of the Galaxy (ATLASGAL), the Australia Telescope Compact Array, and the Millimetre Astronomy Legacy Team Survey at 90GHz (MALT90). According to previous multiwavelength observations, our sample could be divided into two groups: massive young stellar objects and HII regions. Combined with the MALT90 data, we calculated the column densities of N_2_H^+^, C_2_H, HC_3_N, and HNC and found that they are not much different from previous studies made in other massive star-forming regions. However, their abundances are relatively low compared to infrared dark clouds (IRDCs). The abundances of N_2_H^+^ and HNC in our sample are at least 1mag lower than those found in IRDCs, indicating chemical depletions in the relatively hot gas. Besides, the fractional abundances of N_2_H^+^, C_2_H, and HC_3_N seem to decrease as a function of their Lyman continuum fluxes (N_L_), indicating that these molecules could be destroyed by UV photons when HII regions have formed inside. We also find that the C_2_H abundance decreases faster than HC_3_N with respect to N_L_. The abundance of HNC has a tight correlation with that of N_2_H^+^, indicating that it may be also preferentially formed in cold gas. We regard our RMSs as being in a relatively late evolutionary stage of massive star formation.
- ID:
- ivo://CDS.VizieR/J/ApJS/155/149
- Title:
- CH_3_OH 7_0_-6_1_ A^+^ maser sources
- Short Name:
- J/ApJS/155/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Very Large Array survey of 44 massive star-forming regions in the 44GHz 7_0_-6_1_ A^+^ methanol transition; 37 fields showed maser emission. Thirty-one sources were also observed in the 23GHz 9_2_-10_1_ A^+^ methanol line; two fields showed maser emission.
- ID:
- ivo://CDS.VizieR/J/ApJ/646/161
- Title:
- Classification of IR galaxies
- Short Name:
- J/ApJ/646/161
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Mid-infrared diagnostics are presented for a large portion of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample plus archival data from ISO and Spitzer. The SINGS data set includes low- and high-resolution spectral maps and broadband imaging in the infrared for over 160 nuclear and extranuclear regions within 75 nearby galaxies spanning a wide range of morphologies, metallicities, luminosities, and star formation rates. Our main result is that these mid-infrared diagnostics effectively constrain a targets dominant power source. The combination of a high-ionization line index and PAH strength serves as an efficient discriminant between AGNs and star-forming nuclei, confirming progress made with ISO spectroscopy on starbursting and ultraluminous infrared galaxies. The sensitivity of Spitzer allows us to probe fainter nuclear and star-forming regions within galaxy disks.
