Production and evolution of light elements in active star-forming regions

Nature ◽  
1995 ◽  
Vol 373 (6512) ◽  
pp. 318-319 ◽  
Author(s):  
Michel Cassé ◽  
Roland Lehoucq ◽  
Elisabeth Vangloni-Flam
Keyword(s):  
Light Elements ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions

A search for Wolf-Rayet stars in active star forming regions of low mass galaxies - GR8, NGC 2366, IC 2574, and NGC 1569

1993 ◽  
Vol 106 ◽  
pp. 1460 ◽  
Author(s):  
Laurent Drissen ◽  
Jean-Rene Roy ◽  
Anthony F. J. Moffat
Keyword(s):  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Low Mass ◽  
Ngc 1569

scholarly journals THE CO(J=2-1)/CO(J=1-0) Luminosity Ratio in the Orion Giant Molecular Clouds

1994 ◽  
Vol 140 ◽  
pp. 232-233
Author(s):  
Seiichi Sakamoto ◽  
Tetsuo Hasegawa ◽  
Masahiko Hayashi ◽  
Toshihiro Handa ◽  
Tomoharu Oka
Keyword(s):  
Molecular Clouds ◽  
Giant Molecular Clouds ◽  
Large Area ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Galaxies Active

AbstractThe first results of large-area mapping observations of nearby giant molecular clouds in the CO(J=2-1) emission are presented. The CO(J=2-1)/CO(J=1-0) luminosity ratio is 0.75 and 0.62 for the Orion A and B clouds, respectively. These values are consistent with those observed typically in disks of galaxies (−0.6), and are significantly lower than large values (≳1) often observed in active star-forming regions in galaxies. Active star-forming regions in galaxies cannot be explained by ensemble of Orion-like GMCs; they may contain a different population of molecular clouds with high J-2-1/J=1-0 luminosity ratio.

scholarly journals Galactic Rotation Parameters Based on Stars from Active Star-Forming Regions with Data from the Gaia DR2 Catalogue

2020 ◽  
Vol 46 (6) ◽  
pp. 370-378
Author(s):  
O. I. Krisanova ◽  
V. V. Bobylev ◽  
A. T. Bajkova
Keyword(s):  
Galactic Rotation ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Rotation Parameters ◽  
Gaia Dr2

Multiwavelength Analysis of Active Star Forming Regions: The Case of NGC 604

2001 ◽  
pp. 259-262
Author(s):  
Rosa M. González Delgado ◽  
Enrique Pérez
Keyword(s):  
Active Star ◽  
Star Forming ◽  
Star Forming Regions

scholarly journals An ultraviolet view of the Luminous Blue Variables

1989 ◽  
Vol 113 ◽  
pp. 51-58
Author(s):  
Steven N. Shore
Keyword(s):  
Small Aperture ◽  
Active Star ◽  
Star Forming ◽  
Luminous Blue Variables ◽  
Star Forming Regions ◽  
Photometric Observations ◽  
International Ultraviolet Explorer ◽  
Ultraviolet Observation ◽  
Mitigating Circumstances

It is, perhaps, tautological to say that the luminous blue variables (LBVs), being luminous and blue, should be ideal targets for space ultraviolet observation. In fact, many have been observed on occasion and these will be discussed in this article. Mitigating circumstances, however, conspire to make this study difficult. The LBVs are rare and tend to be apparently faint, and since they are massive and formed in the plane in our Galaxy and in active star-forming regions in other galaxies, they tend to be heavily reddened. The stars were not really studied at all in the ultraviolet until the launch of theInternational Ultraviolet Explorer Satellite(IUE), with the notable exceptions of photometric observations of several of the galactic stars with ANS and TD-1 andCopernicusobservations of P Cygni (Hutchingset al. 1987).IUE, a small aperture (45 cm) spectrographic satellite, covering the spectral range from 1200 to 3300 A, allows for an adequate characterization of the UV properties of these stars.

scholarly journals Analysis of VLBI Spot Map of H20 Masers for the HII Region Complex IC133 of Spiral Galaxy M33

1996 ◽  
Vol 175 ◽  
pp. 181-182
Author(s):  
Yu Zhi-Yao
Keyword(s):  
Spiral Galaxy ◽  
Spectral Feature ◽  
Hii Region ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Peak Flux ◽  
The Galaxy ◽  
Distinct Features ◽  
Maser Sources

Interstellar H2O masers in the Galaxy occur in active star forming regions. The spectrum often shows multiple distinct features. The VLBI maps reveal that each spectral feature corresponds to emission of spatially distinct maser sources (maser spots), whose sizes are ≈ 1013cm. The maser in M33 is associated with the HII region complex IC133, which has been studied optically by Boulesteix et al. (1974) and Kiwitter and Aller (1981). This maser is the nearest (≤ 1Mpc) extragalactic H2O source visible in the northern sky, although it is not the strongest. It is known to have persisted for over a decade, and its spectra consistently show peak flux densities of ≈ 1.5 Jy and at least 10 features spread over ≈ 50 km s–1 (Huchtmeier, Eckart and Zensus 1988). Using VLBI Greehill et al. (1990) have obtained the positions of 14 H2O maser spots.

scholarly journals Properties of polycyclic aromatic hydrocarbons in the star forming environment in nearby galaxies

2008 ◽  
Vol 4 (S251) ◽  
pp. 241-246
Author(s):  
Itsuki Sakon ◽  
Takashi Onaka ◽  
Daisuke Kato ◽  
Hidehiro Kaneda ◽  
Hirokazu Kataza ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Mid Infrared ◽  
Active Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Ngc 6946 ◽  
Polycyclic Aromatic ◽  
Nearby Galaxies ◽  
Ionization Model ◽  
Photo Ionization

AbstractWe have carried out the mid-infrared slit spectroscopic observations of sources in the LMC and in NGC 6946 with AKARI/IRC. We investigate the properties of the UIR bands in terms of the star forming activities. We find systematically larger ratios of UIR bands in 6–9 μm to 11.2 μm band in active star forming regions than in the quiet regions. This behavior is consistent with the photo-ionization model of PAHs. Our results suggest that the ratios of UIR bands in 6–9 μm to 11.2 μm band can be used as more efficient and vigorous tools to measure the extent of on-going star formation in remote galaxies rather than just the presence or absence of the features themselves.

scholarly journals Photon dominated regions: Observations of [C I] and CO

1997 ◽  
Vol 178 ◽  
pp. 129-140 ◽  
Author(s):  
Jocelyn Keene ◽  
D. C. Lis ◽  
T. G. Phillips ◽  
P. Schilke
Keyword(s):  
Fine Structure ◽  
Ground State ◽  
Structure Transition ◽  
Active Star ◽  
Star Forming ◽  
Interesting Effect ◽  
Star Forming Regions ◽  
Many Sources

Since the construction of the first specialized submillimeter telescopes nearly a decade ago, there has been extensive mapping of astronomical sources in the previously difficult to observe ground-state fine-structure transition of [C I] at 492 GHz. We discuss recent CSO observations of [C I] and 13CO (2 → 1) lines toward bright photon-dominated regions (PDRs). These observations have revealed an interesting effect. In many sources and over a broad range of column densities, the observed intensity of the [C I] line is proportional to that of the 13CO (2 → 1) line with exceptions mainly in dense, active star-forming regions, where C I appears to be under-abundant relative to 13CO. In this paper we quantitatively display this effect.

Spectral Indices of Centimeter Continuum Sources in Star-forming Regions: Implications on the Nature of the Outflow Exciting Sources

1998 ◽  
Vol 116 (6) ◽  
pp. 2953-2964 ◽  
Author(s):  
Guillem Anglada ◽  
Eva Villuendas ◽  
Robert Estalella ◽  
Maria T. Beltrán ◽  
Luis F. Rodríguez ◽  
...  
Keyword(s):  
Spectral Indices ◽  
Star Forming ◽  
Star Forming Regions
Sign in / Sign up

Export Citation Format

Share Document