The extraordinary HH objects near the star-formation region Cepheus A

1986 ◽  
Vol 92 ◽  
pp. 1155 ◽  
Author(s):  
Patrick Hartigan ◽  
Charles J. Lada ◽  
S. Tapia ◽  
John Stocke
Keyword(s):  
Star Formation ◽  
Star Formation Region ◽  
Formation Region ◽  
Hh Objects ◽  
Cepheus A

scholarly journals Ammonia observations towards the Aquila Rift cloud complex

2020 ◽  
Vol 643 ◽  
pp. A178
Author(s):  
Kadirya Tursun ◽  
Jarken Esimbek ◽  
Christian Henkel ◽  
Xindi Tang ◽  
Gang Wu ◽  
...  
Keyword(s):  
Star Formation ◽  
Dust Emission ◽  
Turbulent Energy ◽  
Gravitational Energy ◽  
High Mass ◽  
Kinetic Temperature ◽  
Mass Star ◽  
Dense Gas ◽  
Star Formation Region ◽  
Formation Region

We surveyed the Aquila Rift complex including the Serpens South and W 40 regions in the NH3 (1,1) and (2,2) transitions making use of the Nanshan 26-m telescope. Our observations cover an area of ~ 1.5° × 2.2° (11.4 pc × 16.7 pc). The kinetic temperatures of the dense gas in the Aquila Rift complex obtained from NH3 (2,2)/(1,1) ratios range from 8.9 to 35.0 K with an average of 15.3 ± 6.1 K (errors are standard deviations of the mean). Low gas temperatures are associated with Serpens South ranging from 8.9 to 16.8 K with an average of 12.3 ± 1.7 K, while dense gas in the W 40 region shows higher temperatures ranging from 17.7 to 35.0 K with an average of 25.1 ± 4.9 K. A comparison of kinetic temperatures derived from para-NH3 (2,2)/(1,1) against HiGal dust temperatures indicates that the gas and dust temperatures are in agreement in the low-mass-star formation region of Serpens South. In the high-mass-star formation region W 40, the measured gas kinetic temperatures are higher than those of the dust. The turbulent component of the velocity dispersion of NH3 (1,1) is found to be positively correlated with the gas kinetic temperature, which indicates that the dense gas may be heated by dissipation of turbulent energy. For the fractional total-NH3 (para+ortho) abundance obtained by a comparison with Herschel infrared continuum data representing dust emission, we find values from 0.1 ×10−8 to 2.1 ×10−7 with an average of 6.9 (±4.5) × 10−8. Serpens South also shows a fractional total-NH3 (para+ortho) abundance ranging from 0.2 ×10−8 to 2.1 ×10−7 with an average of 8.6 (±3.8) × 10−8. In W 40, values are lower, between 0.1 and 4.3 ×10−8 with an average of 1.6 (±1.4) × 10−8. Weak velocity gradients demonstrate that the rotational energy is a negligible fraction of the gravitational energy. In W 40, gas and dust temperatures are not strongly dependent on the projected distance to the recently formed massive stars. Overall, the morphology of the mapped region is ring-like, with strong emission at lower and weak emission at higher Galactic longitudes. However, the presence of a physical connection between the two parts remains questionable.

A Survey of Emission-Line Stars in the CMa Star Formation Region

1986 ◽  
pp. 311-315
Author(s):  
Suhardja D. Wiramihardja ◽  
Tomokazu Kogure ◽  
Makoto Nakano ◽  
Shigeomi Yoshida ◽  
Ken’ichi Tatematsu
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Star Formation Region ◽  
Formation Region

scholarly journals A MID-INFRARED VIEW OF THE HIGH MASS STAR FORMATION REGION W51A

2016 ◽  
Vol 825 (1) ◽  
pp. 54 ◽  
Author(s):  
C. L. Barbosa ◽  
R. D. Blum ◽  
A. Damineli ◽  
P. S. Conti ◽  
D. M. Gusmão
Keyword(s):  
Star Formation ◽  
High Mass ◽  
Mass Star ◽  
Mid Infrared ◽  
Star Formation Region ◽  
Formation Region

scholarly journals The Kinematic Structure of the Supergiant Shell LMC 2

1999 ◽  
Vol 190 ◽  
pp. 156-157
Author(s):  
Sean Points ◽  
You-Hua Chu ◽  
Sungeun Kim ◽  
Robert Gruendl ◽  
R. Chris Smith ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Large Magellanic Cloud ◽  
Kinematic Structure ◽  
Filamentary Structure ◽  
Star Formation Region ◽  
Formation Region ◽  
Active Star ◽  
X Ray ◽  
The North

LMC2 was one of the first supergiant shells in the Large Magellanic Cloud (LMC) to be identified, based on the detection of long, curved Hα filaments extending over 900 pc (Goudis & Meaburn 1978). LMC 2 is located to the east of the active star formation region south of 30 Doradus. LMC 2 is a spectacular supergiant shell in the LMC, having the most coherent filamentary structure and the highest X-ray surface brightness. As shown in Fig. 1, the diffuse X-ray emission from LMC 2 is bounded by the Hα filaments in the north and east. A bright X-ray arc is seen in the southwest quadrant, extending from N 158 and N 159.

scholarly journals VLBA Imaging of 12.2 GHz Methanol Masers

1998 ◽  
Vol 164 ◽  
pp. 375-376
Author(s):  
S. P. Ellingsen ◽  
P.M. McCulloch ◽  
P. J. Diamond ◽  
R. P. Norris
Keyword(s):  
Star Formation ◽  
Velocity Distribution ◽  
Massive Star ◽  
Star Formation Region ◽  
Formation Region ◽  
Maser Emission ◽  
Methanol Maser ◽  
Upper Limit ◽  
Methanol Masers ◽  
Right Ascension

AbstractWe have used the VLBA to image the 12.2 GHz (20-3−1 E) masing transition of methanol toward the massive star formation region G345.01+1.79. The maser spots are distributed in a curved structure with a near monotonic velocity distribution along the curve. The cluster of maser emission covers an area of approximately 200 milli-arcseconds in right ascension and 70 milli-arcseconds in declination.Comparison of the positions of the 12.2 GHz methanol maser spots in G345.01+1.79 as determined from the 1995 VLBA observations with 1988 Parkes-Tidbinbilla Interferometer observations shows that the relative positions of the maser spots detected in both epochs has changed by less than 5 milli-arcseconds during that interval. Assuming a distance of 2.3 kpc to G345.01+1.79 implies an upper limit on the relative tangential velocities of the maser spots of 7 km s−1.

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