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Start Over Subject interstellar clouds Publisher CDS Content Level Research
1. DCld303-14.8 & Thumbprint Nebula JHKs phot.
ID:
ivo://CDS.VizieR/J/A+A/463/1029
Title:
DCld303-14.8 & Thumbprint Nebula JHKs phot.
Short Name:
J/A+A/463/1029
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of radial density structure of the star forming globule, DCld303.8-14.2 (DC303), and a non-star forming globule, Thumbprint Nebula (TPN), using near-infrared data taken with the ISAAC instrument on the Very Large Telescope. We derive the extinction through the globules using the color excess technique and examine the radial density distribution using Bonnor-Ebert and power-law models.
2. Globules and pillars in Cygnus X
ID:
ivo://CDS.VizieR/J/A+A/653/A108
Title:
Globules and pillars in Cygnus X
Short Name:
J/A+A/653/A108
Date:
22 Feb 2022
Publisher:
CDS
Description:
IRAS 20319+3958 in Cygnus X South is a rare example of a free-floating globule (mass ~240M_{sun}_, length ~1.5pc) with an internal HII region created by the stellar feedback of embedded intermediate-mass stars, in particular, one Herbig Be star. In Schneider et al. (2012A&A...542L..18S) and Djupvik et al. (2017A&A...599A..37D, Cat. J/A+A/599/A37), we proposed that the emission of the far-infrared (FIR) lines of [CII] at 158um and [OI] at 145um in the globule head are mostly due to an internal photodissociation region (PDR). Here, we present a Herschel/HIFI [CII] 158um map of the whole globule and a large set of other FIR lines (mid-to high-J CO lines observed with Herschel/PACS and SPIRE, the [OI] 63um line and the ^12^CO 16->15 line observed with upGREAT on SOFIA), covering the globule head and partly a position in the tail. The [CII] map revealed that the whole globule is probably rotating. Highly collimated, high-velocity [CII] emission is detected close to the Herbig Be star. We performed a PDR analysis using the KOSMA-{tau}PDR code for one position in the head and one in the tail. The observed FIR lines in the head can be reproduced with a two-component model: an extended, non-clumpy outer PDR shell and a clumpy, dense, and thin inner PDR layer, representing the interface between the HII region cavity and the external PDR. The modelled internal UV field of ~2500Go is similar to what we obtained from the Herschel FIR fluxes, but lower than what we estimated from the census of the embedded stars. External illumination from the ~30pc distant Cyg OB2 cluster, producing an UV field of ~150-600Go as an upper limit, is responsible for most of the [CII] emission. For the tail, we modelled the emission with a non-clumpy component, exposed to a UV-field of around 140Go.
3. Globulettes in four HII regions
ID:
ivo://CDS.VizieR/J/AJ/133/1795
Title:
Globulettes in four HII regions
Short Name:
J/AJ/133/1795
Date:
21 Oct 2021
Publisher:
CDS
Description:
Some HII regions surrounding young stellar clusters contain tiny dusty clouds, which on photos look like dark spots or teardrops against a background of nebular emission. From our collection of H{alpha} images of 10 HII regions gathered at the Nordic Optical Telescope, we found 173 such clouds, which we call "globulettes", since they are much smaller than normal globules and form a distinct class of objects. Many globulettes are quite isolated and located far from the molecular shells and elephant trunks associated with the regions. Others are attached to the trunks (or shells), suggesting that globulettes may form as a consequence of erosion of these larger structures. None of our objects appear to contain stellar objects. The globulettes were measured for position, dimension, and orientation, and we find that most objects are smaller than 10kAU.
4. Globulettes in the Carina nebula
ID:
ivo://CDS.VizieR/J/A+A/565/A107
Title:
Globulettes in the Carina nebula
Short Name:
J/A+A/565/A107
Date:
21 Oct 2021
Publisher:
CDS
Description:
Small molecular cloudlets are abundant in many HII regions surrounding newborn stellar clusters. In optical images these so-called globulettes appear as dark silhouettes against the bright nebular background. We aim to make an inventory of the population of globulettes in the Carina nebula complex, and to derive sizes and masses for comparisons with similar objects found in other HII regions. The globulettes were identified from H{alpha} images collected at the Hubble Space Telescope.
5. MAMBO Mapping of c2d Clouds and Cores
ID:
ivo://CDS.VizieR/J/A+A/487/993
Title:
MAMBO Mapping of c2d Clouds and Cores
Short Name:
J/A+A/487/993
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present maps from our MAMBO 1.2mm wavelength dust emission survey of nearby (<500pc) dense starless and star-forming cores. This data was collected to study evolutionary trends among the dense cores and the associated young stellar objects. This survey was specifically designed to complement Spitzer Space Telescope imaging of these regions. The maps are unusually sensitive and rich in structure.
6. Near infrared imaging of cometary globule CG12
ID:
ivo://CDS.VizieR/J/A+A/510/A1
Title:
Near infrared imaging of cometary globule CG12
Short Name:
J/A+A/510/A1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Cometary globule 12 is a relatively little investigated medium- and low mass star forming region 210pc above the Galactic plane. This study sets out to discover the possibly embedded members of the CG 12 stellar cluster, to refine the NIR photometry of the known member stars and to study the star formation activity in CG 12 and its relation to the distribution of molecular gas, dust and mid- to far-infrared emission in the cloud. NIR J, H, and Ks imaging and stellar photometry is used to analyse the stellar content and the structure of CG 12.
7. NIR observations of CG1 and CG2
ID:
ivo://CDS.VizieR/J/A+A/550/A83
Title:
NIR observations of CG1 and CG2
Short Name:
J/A+A/550/A83
Date:
21 Oct 2021
Publisher:
CDS
Description:
Cometary globules CG1 and CG2 are "classical" cometary globules in the Gum Nebula region at a distance of ~300pc. The objective of this study is to examine the mass distribution and the structure of CG1 and CG2 through extinction, and to study the star formation activity in CG1 and CG2. The NIR JHKs photometry is used in creating visual extinction maps.
8. Rosette globulettes and shells in the IR
ID:
ivo://CDS.VizieR/J/A+A/567/A108
Title:
Rosette globulettes and shells in the IR
Short Name:
J/A+A/567/A108
Date:
21 Oct 2021
Publisher:
CDS
Description:
The compressed molecular shells around the central clusters in HII regions break up into morphologically distinct fragments due to the UV light from the central OB stars. Tiny, dense, sub-solar mass clumps called globulettes are one of such distinct features. The objective of this study is to study the globulettes and the shells in the Rosette Nebula. Their extinction, surface brightness in the cores and rims, and density have been estimated through NIR observations. The star-formation activity has also been studied. The NIR JHKs photometry is used in creating visual extinction maps and studying the density of individual globulettes.
9. Rosette Nebula globules
ID:
ivo://CDS.VizieR/J/A+A/605/A82
Title:
Rosette Nebula globules
Short Name:
J/A+A/605/A82
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Rosette nebula is an HII region ionized mainly by the stellar cluster NGC 2244. Elephant trunks, globules, and globulettes are seen at the interface where the HII region and the surrounding molecular shell meet. We have observed a field in the northwestern part of the Rosette nebula where we study the small globules protruding from the shell. Our aim is to measure their properties and study their star-formation history in continuation of our earlier study of the features of the region. We imaged the region in broadband near-infrared (NIR) JsHKs filters and narrowband H_2_ 1-0 S(1), P{beta}, and continuum filters using the SOFI camera at the ESO/NTT. The imaging was used to study the stellar population and surface brightness, create visual extinction maps, and locate star formation. Mid-infrared (MIR) Spitzer IRAC and WISE and optical NOT images were used to further study the star formation and the structure of the globules. The NIR and MIR observations indicate an outflow, which is confirmed with CO observations made with APEX.
10. Starless cores in HCN(J=1-0)
ID:
ivo://CDS.VizieR/J/ApJ/664/928
Title:
Starless cores in HCN(J=1-0)
Short Name:
J/ApJ/664/928
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have carried out a survey toward the central regions of 85 starless cores in HCN(J=1-0) to study inward motions in the cores. Sixty-four cores were detected with HCN lines. The infall asymmetry in the HCN spectra is found to be more prevalent, and more prominent than in any other previously used infall tracers such as CS(J=2-1), DCO^+^(J=2-1), and N2H^+^(J=1-0). We have found a close relation between the intensities of the HCN and N2H^+^ lines.