- ID:
- ivo://CDS.VizieR/J/BaltA/22/223
- Title:
- Sh 2-205 Vilnius photometry
- Short Name:
- J/BaltA/22/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of CCD photometry in the seven-color Vilnius system for 922 stars down to V~17mag in a 1.5 square degree field at the northern edge of the HII region Sh2-205, at the Perseus and Camelopardalis border. Using the intrinsic color indices and photometric reddening-free Q-parameters, two-dimensional spectral types for most stars are determined.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/240/14
- Title:
- SIGGMA: inner galaxy data release
- Short Name:
- J/ApJS/240/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Survey of Ionized Gas of the Galaxy, Made with the Arecibo telescope (SIGGMA) provides a fully sampled view of the radio recombination line (RRL) emission from the portion of the Galactic plane visible with Arecibo. Observations use the Arecibo L-band Feed Array, which has a FWHM beam size of 3.4'. Twelve hydrogen RRLs from H163{alpha} to H174{alpha} are located within the instantaneous bandpass from 1225MHz to 1525MHz. We provide here cubes of average ("stacked") RRL emission for the inner Galaxy region 32{deg}<=l<=70{deg}, |b|<=1.5{deg}, with an angular resolution of 6'. The stacked RRL rms at 5.1km/s velocity resolution is ~0.65mJy/beam, making this the most sensitive large-scale fully sampled RRL survey extant. We use SIGGMA data to catalog 319 RRL detections in the direction of 244 known HII regions, and 108 new detections in the direction of 79 HII region candidates. We identify 11 carbon RRL emission regions, all of which are spatially coincident with known HII regions. We detect RRL emission in the direction of 14 of the 32 supernova remnants (SNRs) found in the survey area. This RRL emission frequently has the same morphology as the SNRs. The RRL velocities give kinematic distances in agreement with those found in the literature, indicating that RRLs may provide an additional tool to constrain distances to SNRs. Finally, we analyze the two bright star-forming complexes: W49 and W51. We discuss the possible origins of the RRL emission in directions of SNRs W49B and W51C.
- ID:
- ivo://CDS.VizieR/J/MNRAS/363/405
- Title:
- SIMBA observations of cold cores
- Short Name:
- J/MNRAS/363/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a 1.2-mm continuum emission survey toward 131 star-forming complexes suspected of undergoing massive star formation. These regions have previously been identified as harbouring a methanol maser and/or a radio continuum source [ultracompact (UC) HII region], the presence of which is in most instances indicative of massive star formation. The 1.2-mm emission was mapped using the SIMBA instrument on the 15-m Swedish ESO Submillimetre Telescope (SEST). Emission is detected toward all of the methanol maser and UC HII regions targeted, as well as towards 20 others lying within the fields mapped, implying that these objects are associated with cold, deeply embedded objects. Interestingly, there are also 20 methanol maser sites and nine UC HII regions within the fields mapped which are devoid of millimetre continuum emission. In addition to the maser and UC HII regions detected, we have also identified 253 other sources within the SIMBA maps. All of these (253) are new sources, detected solely from their millimetre continuum emission. In total, 404 sources are detected, representing four classes of sources which are distinguished by the presence of the different combination of associated tracers.
- ID:
- ivo://CDS.VizieR/J/A+A/426/97
- Title:
- SIMBA survey. 1.2-mm/IRAS sources
- Short Name:
- J/A+A/426/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a 1.2mm continuum emission survey toward 146 IRAS sources thought to harbour high-mass star forming regions. The sources have FIR colors typical of UCHII regions and were detected in the CS (2-1) line survey of Bronfman et al. (1996, Cat. J/A+AS/115/81). Regions of 15'x10', centered on each IRAS source, were mapped with an angular resolution of ~24", using the SIMBA array on the SEST telescope. 1.2mm emission was detected toward all IRAS sources. We find that the dust cores associated with these sources have typical sizes of 0.4pc and masses of 5x10^3^M_{sun}. Dust temperatures and luminosities, derived from the SED, are typically 32K and 2.3x10^5^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A94
- Title:
- SiO and HCO+ massive molecular outflows
- Short Name:
- J/A+A/557/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study of 14 molecular outflows associated with high-mass star formation. We used the IRAM30m telescope to characterize the outflow emission in the SiO(2-1), SiO(5-4) and HCO^+^(1-0) lines. We detect outflows in all the 14 high-mass star-forming regions in both, the SiO and HCO^+^ lines. Six of the fourteen outflows show bipolarity. The physical parameters derived for these outflows are consistent with outflows powered by massive young stellar objects with luminosities in the range 10^3^-10^4^L_{sun}_. We found a decrease of the SiO abundance (from 10^-8^ to 10^-9^) as the object evolves in time, while there are hints of a possible increase of the HCO^+^ outflow energetics with time. These results suggest a scenario in which SiO is largely enhanced in the first evolutionary stages, probably due to strong shocks produced by the protostellar jet. As the object evolves, the power of the jet would decrease and so does the SiO abundance. During this process, however, the material surrounding the protostar would have been swept up by the jet, and the outflow activity, traced by entrained molecular material (HCO^+^), would increase with time.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A16
- Title:
- Six LMC star forming region spectra
- Short Name:
- J/A+A/600/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The kinetic temperature of molecular clouds is a fundamental physical parameter affecting star formation and the initial mass function. The Large Magellanic Cloud (LMC), the closest star forming galaxy with low metallicity, provides an ideal laboratory to study star formation in such an environment. The classical dense molecular gas thermometer NH_3_ is rarely available in a low metallicity environment because of photoionization and a lack of nitrogen atoms. Our goal is to directly measure the gas kinetic temperature with formaldehyde toward six star-forming regions in the LMC. Three rotational transitions (J_KAKC_ = 3_03_-2_02_, 3_22_-2_21_, and 3_21_-2_20_) of para-H_2_CO near 218GHz were observed with the Atacama Pathfinder EXperiment (APEX) 12m telescope toward six star forming regions in the LMC. Those data are complemented by C^18^O 2-1 spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A31
- Title:
- SMC blob N26 multiband photometry
- Short Name:
- J/A+A/564/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-excitation compact HII regions of the Magellanic Clouds are sites of recent massive star formation in low metallicity environments. Detailed study of these regions and their environments using high-spatial resolution observations is necessary to better understand massive star formation, which is still an unsolved problem. We aim at a detailed study of the Small Magellanic Cloud compact HII region N26, which is only ~4" in diameter. This study is based on high spatial resolution imaging (~0.1"-0.3") in JHKs and L' bands, using the VLT equipped with the NAOS adaptive optics system. A larger region (~50pcx76pc) was also imaged at medium spatial resolution, using the ESO 2.2m telescope in optical wavelengths. We also used the JHKs archival data from the IRSF survey and the Spitzer Space Telescope SAGE-SMC survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/744/20
- Title:
- S^4^MC project: 6 star forming regions PAHs
- Short Name:
- J/ApJ/744/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of mid-infrared spectroscopic mapping observations of six star-forming regions in the Small Magellanic Cloud (SMC) from the Spitzer Spectroscopic Survey of the SMC (S^4^MC). We detect the mid-IR emission from polycyclic aromatic hydrocarbons (PAHs) in all of the mapped regions, greatly increasing the range of environments where PAHs have been spectroscopically detected in the SMC. We investigate the variations of the mid-IR bands in each region and compare our results to studies of the PAH bands in the SINGS sample and in a sample of low-metallicity starburst galaxies. PAH emission in the SMC is characterized by low ratios of the 6-9um features relative to the 11.3um feature and weak 8.6 and 17.0um features. Interpreting these band ratios in the light of laboratory and theoretical studies, we find that PAHs in the SMC tend to be smaller and less ionized than those in higher metallicity galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/327
- Title:
- S3MC: YSOs in N66, in SMC
- Short Name:
- J/ApJ/669/327
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Spitzer Space Telescope observations from the Spitzer Survey of the Small Magellanic Cloud (S^3^MC) to study the young stellar content of N66, the largest and brightest HII region in the SMC. In addition to large numbers of normal stars, we detect a significant population of bright, red infrared sources that we identify as likely to be young stellar objects (YSOs). We use spectral energy distribution (SED) fits to classify objects as ordinary (main-sequence or red giant) stars, asymptotic giant branch stars, background galaxies, and YSOs.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A110
- Title:
- SN II in host HII regions
- Short Name:
- J/A+A/589/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectral modelling of typeII supernova atmospheres indicates a clear dependence of metal line strengths on progenitor metallicity. This dependence motivates further work to evaluate the accuracy with which these supernovae can be used as environment metallicity indicators. To assess this accuracy we present a sample of type II supernova host HII-region spectroscopy, from which environment oxygen abundances have been derived. These environment abundances are compared to the observed strength of metal lines in supernova spectra. Combining our sample with measurements from the literature, we present oxygen abundances of 119 host HII regions by extracting emission line fluxes and using abundance diagnostics. These abundances are then compared to equivalent widths of FeII 5018{AA} at various time and colour epochs. Our distribution of inferred type II supernova host HII-region abundances has a range of ~0.6dex. We confirm the dearth of type II supernovae exploding at metallicities lower than those found (on average) in the Large Magellanic Cloud. The equivalent width of FeII 5018{AA} at 50 days post-explosion shows a statistically significant correlation with host HII-region oxygen abundance. The strength of this correlation increases if one excludes abundance measurements derived far from supernova explosion sites. The correlation significance also increases if we only analyse a "gold" IIP sample, and if a colour epoch is used in place of time. In addition, no evidence is found of a correlation between progenitor metallicity and supernova light-curve or spectral properties - except for that stated above with respect to FeII 5018{AA} equivalent widths - suggesting progenitor metallicity is not a driving factor in producing the diversity that is observed in our sample. This study provides observational evidence of the usefulness of typeII supernovae as metallicity indicators. We finish with a discussion of the methodology needed to use supernova spectra as independent metallicity diagnostics throughout the Universe.
