NGC7538 Irs1 N: Modeling a Circumstellar Maser Disk
نویسندگان
چکیده
منابع مشابه
Detection of DCO in a circumstellar disk
We report the first detection of DCO in a circumstellar disk. The DCO J=5–4 line at 360.169 GHz is observed with the 15m James Clerk Maxwell Telescope in the disk around the pre-main sequence star TW Hya. Together with measurements of the HCO and HCO J=4–3 lines, this allows an accurate determination of the DCO/HCO ratio in this disk. The inferred value of 0.035±0.015 is close to that found in ...
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We present VLBI observations of 6.7 and 12.2 GHz methanol masers in the star forming region NGC7538. Our results show the existence of two groups of masers. The first group exhibits a linear velocity gradient and forms a line in our VLBI map which is consistent with a rotating disc of masers seen edge-on around a massive star. The second group of masers are blueshifted with respect to the first...
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We report the first VLBI map of the v=0 J=1–0 maser line of 29 SiO in the long-period variable star IRC +10011. We have found that this maser emission is composed of multiple spots distributed in an incomplete ring, suggesting that this maser is also amplified tangentially, as already proposed in other SiO circumstellar masers. We present also VLBI maps for the 7 mm 28 SiO v=1 and 2 J=1–0 and t...
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Observations show that 1612MHz masers of OH/IR stars can fade on a timescale of a decade. This fading is probably associated with the switch from rapid mass loss, which is ultimately linked with an internal He-shell flash, to the much slower mass loss supported by more quiescent conditions. We study the observed maser decay with a composite computational model, comprising a time-dependent chemi...
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ژورنال
عنوان ژورنال: Astrophysics and Space Science
سال: 2005
ISSN: 0004-640X,1572-946X
DOI: 10.1007/s10509-005-3696-8