- ID:
- ivo://CDS.VizieR/J/A+A/586/A50
- Title:
- Central Molecular Zone H2CO temperature maps
- Short Name:
- J/A+A/586/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic center is the closest region in which we can study star formation under extreme physical conditions like those in high-redshift galaxies. We measure the temperature of the dense gas in the Central Molecular Zone (CMZ) and examine what drives it. We have mapped the inner 300pc of the CMZ in the temperature-sensitive J=3-2 para-formaldehyde (p-H_2_CO) transitions. We use the 3_2,1_-2_2,0_/3_0,3_-2_0,2_ line ratio to determine the gas temperature in n~10^4^-10^5^cm^-3^ gas. We produce temperature maps and cubes with 30" and 1km/s resolution and publish all data in FITS form; they can be recovered from digital object identifier doi:10.7910/DVN/27601.
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Search Results
- ID:
- ivo://CDS.VizieR/J/PASJ/67/90
- Title:
- Central Molecular Zone in H^13^CO^+^
- Short Name:
- J/PASJ/67/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a high-resolution wide-field imaging observation of the Central Molecular Zone (CMZ) in H^13^CO^+^ J=1-0 and SiO v=0, J=2-1 emission lines using the 45-m telescope at the Nobeyama Radio Observatory in order to depict the high-density molecular gas mass distribution and explore molecular gas affected by interstellar shocks. By using the clumpfind algorithm we identify 114 molecular clumps in the H^13^CO^+^ data cube.
- ID:
- ivo://CDS.VizieR/J/ApJS/115/59
- Title:
- Cepheus flare molecular clouds
- Short Name:
- J/ApJS/115/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of an objective prism Schmidt survey are combined with IRAS survey data in order to assess the star-forming activity in the Cepheus Flare, a nearby giant molecular cloud complex at ~15{deg} above the Galactic equator. The distribution of absorbing matter along the line of sight was also studied. The Wolf diagrams, displaying the cumulative distribution of field star distance moduli, show that the interstellar matter in this region is concentrated at three characteristic distances: 200, 300, and 450pc. The three components, though partly overlapping, can be separated along the Galactic latitude. Within the area of the Cepheus Flare, distances are determined for 14 Lynds dark clouds and for some other clouds.
- ID:
- ivo://CDS.VizieR/J/A+A/535/A2
- Title:
- Chamaeleon III 870um sources maps
- Short Name:
- J/A+A/535/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby Chamaeleon molecular cloud complex is a good laboratory for studying the process of low-mass star formation because it consists of three clouds with very different properties. Chamaeleon III does not show any sign of star formation, while star formation has been very active in Chamaeleon I and may already be finishing. Our goal is to determine whether star formation can proceed in Cha III by searching for prestellar cores, and to compare the results to our recent survey of Cha I.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A145
- Title:
- Chamaeleon I 870um sources
- Short Name:
- J/A+A/527/A145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chamaeleon I is the most active region in terms of star formation in the Chamaeleon molecular cloud complex. Although it is one of the nearest low-mass star forming regions, its population of prestellar and protostellar cores is not known and a controversy exists concerning its history of star formation. Our goal is to search for prestellar and protostellar cores and characterize the earliest stages of star formation in this cloud.
- ID:
- ivo://CDS.VizieR/J/PASJ/55/635
- Title:
- Chandra observations of Monoceros R2
- Short Name:
- J/PASJ/55/635
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the results of the Chandra ACIS-I observation on the central region of the Monoceros R2 cloud (Mon R2), a high-mass star-forming region (SFR) at a distance of 830pc. With a deep exposure of ~100ks, we detected 368 X-ray sources, ~80% of which were identified with the near-infrared (NIR) counterparts. We systematically analyzed the spectra and time variability of most of the X-ray emitting sources and provided a comprehensive X-ray source catalog for the first time. Using the J-, H- and K-bands magnitudes of the NIR counterparts, we estimated the evolutionary phase (classical T Tauri stars and weak-lined T Tauri stars) and the mass of the X-ray emitting sources, and analyzed the X-ray properties as a function of the age and mass.
- ID:
- ivo://CDS.VizieR/J/ApJ/696/47
- Title:
- Chandra study of Rosette star-forming complex. II.
- Short Name:
- J/ApJ/696/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore here the young stellar populations in the Rosette Molecular Cloud (RMC) region with high spatial resolution X-ray images from the Chandra X-ray Observatory, which are effective in locating weak-lined T Tauri stars as well as disk-bearing young stars. A total of 395 X-ray point sources are detected, 299 of which (76%) have an optical or near-infrared (NIR) counterpart identified from deep FLAMINGOS images. From X-ray and mass sensitivity limits, we infer a total population of ~1700 young stars in the survey region. Based on smoothed stellar surface density maps, we investigate the spatial distribution of the X-ray sources and define three distinctive structures and substructures within them. Structures B and C are associated with previously known embedded IR clusters, while structure A is a new X-ray-identified unobscured cluster. A high-mass protostar RMCX 89=IRAS 06306+0437 and its associated sparse cluster are studied.
- ID:
- ivo://CDS.VizieR/J/ApJS/163/306
- Title:
- Chandra study of the Cep B star-forming region
- Short Name:
- J/ApJS/163/306
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Cepheus B (Cep B) molecular cloud and a portion of the nearby Cep OB3b OB association, one of the most active regions of star formation within 1kpc, have been observed with the ACIS detector on board the Chandra X-Ray Observatory. We detect 431 X-ray sources, of which 89% are confidently identified as clustered premain-sequence (PMS) stars.
- ID:
- ivo://CDS.VizieR/J/A+A/547/A33
- Title:
- Chemical reactions for a deuteration network
- Short Name:
- J/A+A/547/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ground-state rotational ortho-D2H+(1,1,1-0,0,0) transition at 1476.6GHz in the prestellar core 16293E has been searched for with the Herschel/HIFI instrument, within the CHESS (Chemical HErschel Surveys of Star forming regions) Key Program. The line has not been detected at the 21mK.km/s level (3 sigma integrated line intensity). We used the ortho-H2D+ 110-111 transition and para-D2H+ 110-101 transition detected in this source to determine an upper limit on the ortho-to-para D2H+ ratio as well as the para-D2H+/ortho-H2D+ ratio from a non-LTE analysis. We then compared our chemical modeling with the observations in order to estimate the CO depletion as well as the H2 density and kinetic temperature at the position observed. The chemical network is provided in the kida.dat file.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A88
- Title:
- Chemistry in infrared dark clouds
- Short Name:
- J/A+A/527/A88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive stars play an important role in shaping the structure of galaxies. Infrared dark clouds (IRDCs), with their low temperatures and high densities, have been identified as the potential birthplaces of massive stars. In order to understand the formation processes of massive stars, the physical and chemical conditions in infrared dark clouds have to be characterized. The goal of this paper is to investigate the chemical composition of a sample of southern infrared dark clouds. One important aspect of the observations is to check, whether the molecular abundances in IRDCs are similar to the low-mass pre-stellar cores, or if they show signatures of more evolved evolutionary stages. We performed observations toward 15 IRDCs in the frequency range between 86 and 93GHz using the 22-m Mopra radio telescope. In total, 13 molecular species comprising N_2_H^+^, ^13^CS, CH_3_CN, HC_3_N, HNC, HCO^+^, HCN, HNCO, C_2_H, SiO, H^13^CO^+^, H^13^CN, and CH_3_C_2_H were observed for all targets. Hence, we included in general species appropriate for elevated densities, where some of them trace the more quiescent gas, while others are sensitive to more dynamical processes.
