- ID:
- ivo://CDS.VizieR/J/A+A/507/241
- Title:
- IR and 610MHz observations in MGRO J2019+37
- Short Name:
- J/A+A/507/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- MGROJ2019+37 is an unidentified extended source of very high energy gamma-rays originally reported by the Milagro Collaboration as the brightest TeV source in the Cygnus region. Its extended emission could be powered by either a single or several sources. The GeV pulsar AGL J2020.5+3653 discovered by AGILE and associated with PSR J2021+3651 could contribute to the emission from MGRO J2019+37. The aim of this paper is to identify radio and near-infrared sources in the field of the extended TeV source MGRO J2019+37, and study potential counterparts to explain its emission. We surveyed a region of about 6 square degrees with the Giant Metrewave Radio Telescope (GMRT) at the frequency 610MHz. We also observed the central square degree of this survey in the near-infrared Ks-band using the 3.5m telescope in Calar Alto. Archival X-ray observations of some specific fields are included. VLBI observations of an interesting radio source were performed. We explored possible scenarios to produce the multi-TeV emission from MGRO J2019+37 and studied which of the sources could be the main particle accelerator.
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- ID:
- ivo://CDS.VizieR/J/A+A/468/1001
- Title:
- IRAS 20178+4046 maps at 610 and 1280MHz
- Short Name:
- J/A+A/468/1001
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of the ultra compact HII region associated with IRAS 20178+4046. This enables us to probe the different components associated with this massive star forming region.
- ID:
- ivo://CDS.VizieR/J/ApJ/779/113
- Title:
- IR photometry of YSOs in the W40 region
- Short Name:
- J/ApJ/779/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of the W40 star-forming region using infrared (IR) observations in the UKIRT JHK bands, Spitzer Infrared Array Camera bands, and Herschel PACS bands, 2.12{mu}m H_2_ narrowband imaging, and radio continuum observations from GMRT (610 and 1280MHz), in a field of view (FoV) of ~34'x40'. Archival Spitzer observations in conjunction with near-IR observations are used to identify 1162 Class II/III and 40 Class I sources in the FoV. The nearest-neighbor stellar surface density analysis shows that the majority of these young stellar objects (YSOs) constitute the embedded cluster centered on the high-mass source IRS 1A South. Some YSOs, predominantly the younger population, are distributed along and trace the filamentary structures at lower stellar surface density. The cluster radius is measured to be 0.44pc -- matching well with the extent of radio emission -- with a peak density of 650/pc2. The JHK data are used to map the extinction in the region, which is subsequently used to compute the cloud mass -- 126M_{sun}_ and 71M_{sun}_ for the central cluster and the northern IRS 5 region, respectively. H_2_ narrowband imaging shows significant emission, which prominently resembles fluorescent emission arising at the borders of dense regions. Radio continuum analysis shows that this region has a blister morphology, with the radio peak coinciding with a protostellar source. Free-free emission spectral energy distribution analysis is used to obtain physical parameters of the overall photoionized region and the IRS 5 sub-region.
- 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/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/ApJ/566/880
- Title:
- ISO-SWS observations of H II regions
- Short Name:
- J/ApJ/566/880
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present mid-infrared Infrared Space Observatory Short-Wavelength Spectrometer (ISO-SWS) observations of the fine-structure emissions lines [Ne II] 12.8{mu}m, [Ne III] 15.6{mu}m, [Ne III] 36.0{mu}m, [Ar II] 6.99{mu}m, [Ar III] 8.99{mu}m, [S III] 18.7{mu}m, [S III] 33.5{mu}m, and [S IV] 10.5{mu}m and the recombination lines Br{alpha} and Br{beta} n a sample of 112 Galactic H II regions and 37 nearby extra-Galactic H II regions in the LMC, SMC, and M33.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/1551
- Title:
- JCMT Gould Belt Survey: Serpens MWC 297
- Short Name:
- J/MNRAS/448/1551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present SCUBA-2 450 and 850{mu}m observations of the Serpens MWC 297 region, part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two-component model of the JCMT beam for a fixed dust opacity spectral index of {beta}=1.8. Within 40-arcsec of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free-free emission with a spectral index of 1.03+/-0.02, consistent with an ultracompact HII region and polar winds/jets. Contamination accounts for 73+/-5 per cent and 82+/-4 per cent of peak flux at 450{mu}m and 850 {mu}m, respectively. The residual thermal disc of the star is almost undetectable at these wavelengths. Young stellar objects (YSOs) are confirmed where SCUBA-2 850{mu}m clumps identified by the fellwalker algorithm coincide with Spitzer Gould Belt Survey detections. We identify 23 objects and use T_bol_ to classify nine YSOs with masses 0.09 to 5.1M_{sun}_. We find two Class 0, one Class 0/I, three Class I and three Class II sources. The mean temperature is 15+/-2K for the nine YSOs and 32+/-4K for the 14 starless clumps. We observe a starless clump with an abnormally high mean temperature of 46+/-2K and conclude that it is radiatively heated by the star MWC 297. Jeans stability provides evidence that radiative heating by the star MWC 297 may be suppressing clump collapse.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/4150
- Title:
- JCMT Gould Belt Survey: W40 complex
- Short Name:
- J/MNRAS/460/4150
- Date:
- 14 Jan 2022 11:14:19
- Publisher:
- CDS
- Description:
- We present SCUBA-2 450{mu}m and 850{mu}m observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby star-forming regions. We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index, {beta}=1.8, and a beam convolution kernel to achieve a common 14.8-arcsec resolution. We identify 82 clumps ranging between 10 and 36K with a mean temperature of 20+/-3K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust. We identify 31 clumps that have cores with densities greater than 10^5^cm^-3^. 13 of these cores contain embedded Class 0/I protostars. Many cores are associated with bright-rimmed clouds seen in Herschel 70{mu}m images. From JCMT HARP observations of the ^12^CO 3-2 line, we find contamination of the 850{mu}m band of up to 20 per cent. We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact HII regions using archival VLA data and find the contribution is limited to individual stars, accounting for 9 per cent of flux per beam at 450{mu}m or 12 per cent at 850{mu}m in these cases. We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region, favouring Jeans stable clouds in the warm east and fragmentation in the cool west.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A122
- Title:
- JHK and IRAC photometry of Sh2-90 YSOs
- Short Name:
- J/A+A/566/A122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the star formation activity in the molecular complex associated with the Galactic HII region Sh2-90. We obtain the distribution of the ionized and cold neutral gas using radio-continuum and Herschel observations. We use near-infrared and Spitzer data to investigate the stellar content of the complex. We discuss the evolutionary status of embedded massive young stellar objects (MYSOs) using their spectral energy distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/450/253
- Title:
- JHKL photometry of RCW57/NGC3576
- Short Name:
- J/A+A/450/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- L-band data of RCW 57 at 3.5 micron taken with SPIREX (South Pole Infrared Explorer) is presented. The photometry was combined with 2MASS JHK data at 1.25 -2.2 micron. Colour-colour and colour-magnitude diagrams are constructed and used to determine the sources with infrared excess. These are interpreted as circumstellar disks, and enable the fraction of sources with disks (the cluster disk fraction or CDF) to be determined. We find that more than 50% of the sources detected at L-band in RCW 57 have an IR-excess.
