scholarly journals Unveiling the Unseen: The Mid-IR Galactic Disk

2009 ◽  
Vol 5 (H15) ◽  
pp. 787-787
Author(s):  
Ed Churchwell
Keyword(s):  
Galactic Disk ◽  
Young Stellar Objects ◽  
Physical Processes ◽  
Stellar Objects ◽  
Mid Infrared ◽  
Dark Clouds ◽  
The Galaxy ◽  
Polycyclic Aromatic ◽  
Star Formation Regions ◽  
Infrared Dark Clouds

AbstractThe Spitzer mid-infrared (MIR) surveys, Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and MIPSGAL have revealed a new view of the disk of the Milky Way. Hallmarks of the Galactic disk at MIR wavelengths with spatial resolution <2″ are bubbles/HII regions, infrared dark clouds, young stellar objects (YSOs)/star formation regions, diffuse dust and extended polycyclic aromatic hydrocarbons (PAHs), and more than 100 million publically available archived stars with measured flux densities at 7 wavelengths and positions accurate to 0.1″. At mid-IR wavelengths, the cool components in the Galaxy are preferentially bright and highlight physical processes that are not obvious at other wavelength regimes.

SiO as a chemical signature of outflows from bright, compact sources in MSX IR-dark clouds

2004 ◽  
Vol 82 (6) ◽  
pp. 740-743 ◽  
Author(s):  
P A Feldman ◽  
R O Redman ◽  
L W Avery ◽  
J Di Francesco ◽  
J D Fiege ◽  
...  
Keyword(s):  
Star Formation ◽  
Young Stellar Objects ◽  
Line Profiles ◽  
Bipolar Outflows ◽  
Dark Cloud ◽  
Stellar Objects ◽  
Dark Clouds ◽  
Dense Cores ◽  
Infrared Dark Clouds ◽  
Compact Sources

The line profiles of dense cores in infrared-dark clouds indicate the presence of young stellar objects (YSOs), but the youth of the YSOs and the large distances to the clouds make it difficult to distinguish the outflows that normally accompany star formation from turbulence within the cloud. We report here the first unambiguous identification of a bipolar outflow from a young stellar object (YSO) in an infrared-dark cloud, using observations of SiO to distinguish the relatively small amounts of gas in the outflow from the rest of the ambient cloud. Key words: infrared-dark clouds, star formation, bipolar outflows, SiO, G81.56+0.10.

scholarly journals Identification of Class I Methanol Masers with Objects of Near and Mid-Infrared Bands and the Third Version of the Class I Methanol Maser (MMI) Catalog

2012 ◽  
Vol 8 (S287) ◽  
pp. 280-281
Author(s):  
Olga Bayandina ◽  
Irina Val'tts ◽  
Grigorii Larionov
Keyword(s):  
Galactic Plane ◽  
Short Wave ◽  
Class I ◽  
Young Stellar Objects ◽  
Bipolar Outflows ◽  
Stellar Objects ◽  
Mid Infrared ◽  
Dark Clouds ◽  
The Third ◽  
Methanol Masers

AbstractAn identification has been conducted of class I methanol masers with 1) short-wave infrared objects EGO (extended green objects) - tracer bipolar outflow of matter in young stellar objects, and 2) isolated pre-protostellar gas-dust cores of the interstellar medium which are observed in absorption in the mid-infrared in the Galactic plane. It is shown that more than 50% of class I methanol masers are identified with bipolar outflows, considering the EGO as bipolar outflows (as compared with the result of 22% in the first version of the MMI catalog that contains no information about EGO). 99 from 139 class I methanol masers (71%) are identified with SDC. Thus, it seems possible that the MMI can be formed in isolated self-gravitating condensations, which are the silhouette of dark clouds - IRDC and SDC.

Evidence for the absorption of crystalline silicates at 11.1 $\mu$m in the spectra of the nucleus of the Circinus galaxy

2019 ◽  
Vol 488 (1) ◽  
pp. L75-L79
Author(s):  
Tho Do Duy ◽  
Warrick A Lawson
Keyword(s):  
Grain Size ◽  
Milky Way ◽  
Young Stellar Objects ◽  
Line Of Sight ◽  
Stellar Objects ◽  
Mid Infrared ◽  
Profile Shape ◽  
The Earth ◽  
Star Formation Regions ◽  
Galaxy Nucleus

Abstract Several mid-infrared spectra of the Circinus galaxy nucleus taken with T-ReCS on Gemini South and MIDI on VLTI have consistently shown an inflection centred around 11 $\mu$m. We ascribe this feature to the absorption of crystalline silicate, based on their similarity in profile shape and improvement in fitting quality using a partially crystalline silicate model, compared to entirely amorphous models. Spectral fits reveal a fraction of 0.6–2.0 per cent of crystalline forsterite in the nucleus of the Circinus galaxy, which is similar to the values obtained for the interstellar medium (ISM) of the Milky Way. This is probably the first detection of crystalline silicate absorption in the nucleus of this Seyfert 2 galaxy. In addition, the presence of large grain-size amorphous silicates, together with the similarity in profile shape of the optical depth of Circinus with those of young stellar objects in the Milky Way, implies that most of the contribution to the spectra of Circinus comes from dust in the star formation regions near the centre of the nucleus or along the line of sight to the Earth, rather than in the ISM of Circinus. We also compare our optical depths of Circinus with those in previous studies.

scholarly journals A New Comprehensive Catalogue of Infrared Dark Clouds

2009 ◽  
Vol 5 (H15) ◽  
pp. 796-796
Author(s):  
G. A. Fuller ◽  
N. Peretto
Keyword(s):  
Star Formation ◽  
Initial Conditions ◽  
Future Studies ◽  
Dark Clouds ◽  
Star Formation Activity ◽  
Extraction Algorithm ◽  
The Galaxy ◽  
The Individual ◽  
Density Image ◽  
Infrared Dark Clouds

AbstractTo better characterise infrared dark clouds (IRDCs), and the star formation within them, a comprehensive catalogue of IRDCs has been constructed from the Spitzer GLIMPSE and MIPSGAL archival data. Mosaicing the individual survey blocks together, we have used a new extraction method to identify dark clouds up to 30′ in size, and produce a column density image of each cloud. In total the catalogue contains over 11,000 clouds, defined as connected regions with 8 micron optical depth > 0.35 (corresponding to column densities < 1022 cm−2). The extraction algorithm also identifies sub-structures (fragments) within each cloud. These Spitzer dark clouds (SDCs) range in mass from 10M⊙ to 104M⊙. About 80% of the SDCs were previously unidentified. Only ~ 30% of the SDCs are associated with 24μm point-like sources, leaving the majority of these clouds with no apparent sign of star formation activity. This new catalogue provides an important new resource for future studies of the initial conditions of star formation in the Galaxy.

Gemini Mid-Infrared Imaging of Massive Young Stellar Objects in NGC 3576

2003 ◽  
Vol 126 (5) ◽  
pp. 2411-2420 ◽  
Author(s):  
C. L. Barbosa ◽  
A. Damineli ◽  
R. D. Blum ◽  
P. S. Conti
Keyword(s):  
Infrared Imaging ◽  
Young Stellar Objects ◽  
Stellar Objects ◽  
Mid Infrared

scholarly journals MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS

2012 ◽  
Vol 201 (2) ◽  
pp. 11 ◽  
Author(s):  
Á. Kóspál ◽  
P. Ábrahám ◽  
J. A. Acosta-Pulido ◽  
C. P. Dullemond ◽  
Th. Henning ◽  
...  
Keyword(s):  
Young Stellar Objects ◽  
Spectral Variability ◽  
Stellar Objects ◽  
Mid Infrared ◽  
Infrared Spectral

scholarly journals Solid State DIBs

2013 ◽  
Vol 9 (S297) ◽  
pp. 359-363
Author(s):  
H. Linnartz
Keyword(s):  
Solid State ◽  
Low Temperatures ◽  
Molecular Hydrogen ◽  
Experimental Approach ◽  
Amorphous Solid ◽  
Young Stellar Objects ◽  
Stellar Objects ◽  
Dark Clouds ◽  
Diffuse Interstellar Bands ◽  
Interstellar Ice

AbstractThe diffuse interstellar bands are not due to solid state species. However, under the explicit assumption that DIB carriers survive the transfer from translucent to dark clouds, it is expected that for the low temperatures in the dense interstellar medium also DIB carriers accrete onto dust grains. Like all other molecules, apart from molecular hydrogen, they will get embedded in an ice matrix that largely consists of amorphous solid water. This offers - in principle - a tool to search for DIBs in complete different environments, both in space (i.e., towards embedded young stellar objects) and in the laboratory, namely in the solid state simulating interstellar ice analogues. Currently experiments are ongoing in the Sackler Laboratory for Astrophysics at Leiden Observatory to record optical ice spectra of potential DIB carriers. For this a new experimental approach has been developed. Its performance and potential are discussed.

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