8 research outputs found
Evidence for variable outflows in the Young Stellar Object V645 Cygni
As part of the Red MSX Source Survey of Massive Young Stellar Objects (MYSOs)
we have conducted multi-wavelength follow up observations of the well-known
object V645 Cygni. We present our data on this object, whose near-infrared
spectrum is exceptional and place these in context with previous observations.
Our observations of V645 Cyg included near/mid infrared imaging observations,
13CO 2-1 line observations and high signal-to-noise velocity resolved
near-infrared spectroscopy. The spectrum shows P-Cygni hydrogen Brackett
emission, consistent with a high velocity stellar wind. A red-shifted emission
component to a number of near-IR emission lines was also uncovered. This is
associated with a similar component in the H alpha line. V645 Cyg is also found
to have variable CO first overtone bandhead emission. The data clearly indicate
that the outflow of V645 Cyg is variable. The unidentified feature in a
previously published optical spectrum is identified with a receding outflow at
2000 km per second. The nature of this feature, which is found in hydrogen and
helium atomic lines and CO molecular lines remains a puzzle.Comment: 7 pages including 4 figures. Accepted for publication in A&
The RMS Survey: Mid-Infrared Observations of Candidate Massive YSOs in the Southern Hemisphere
Abridged abstract: The Red MSX Source (RMS) survey is an ongoing effort to
return a large, well-selected sample of massive young stellar objects (MYSOs)
within our Galaxy. A series of ground-based follow-up observations are being
undertaken in order to remove contaminant objects from our list of 2000
candidates, and to begin characterising these MYSOs. As a part of these
follow-up observations, high resolution (~1") mid-IR imaging aids the
identification of contaminant objects which are resolved (UCHII regions, PN) as
opposed to those which are unresolved (YSOs, evolved stars) as well as
identifying YSOs near UCHII regions and other multiple sources. We present 10.4
micron imaging observations for 346 candidate MYSOs in the RMS survey in the
Southern Hemisphere, primarily outside the region covered by the GLIMPSE
Spitzer Legacy Survey. These were obtained using TIMMI2 on the ESO 3.6m
telescope in La Silla, Chile. Our photometric accuracy is of order 0.05Jy, and
our astrometric accuracy is 0.8", which is an improvement over the nominal 2"
accuracy of the MSX PSC.Comment: 9 page paper accepted to A&A. Online data for table 2 and figure 1
will be available in the published online version of this paper via A&A. The
paper contains 7 figures and 3 table
A Herschel resolved far-infrared dust ring around HD 207129
Dusty debris discs around main sequence stars are thought to be the result of
continuous collisional grinding of planetesimals in the system. The majority of
these systems are unresolved and analysis of the dust properties is limited by
the lack of information regarding the dust location.vThe Herschel DUNES key
program is observing 133 nearby, Sun-like stars (<20 pc, FGK spectral type) in
a volume limited survey to constrain the absolute incidence of cold dust around
these stars by detection of far infrared excess emission at flux levels
comparable to the Edgeworth-Kuiper belt (EKB). We have observed the Sun-like
star HD 207129 with Herschel PACS and SPIRE. In all three PACS bands we resolve
a ring-like structure consistent with scattered light observations. Using
{\alpha} Bo\"otis as a reference point spread function (PSF), we deconvolved
the images, clearly resolving the inner gap in the disc at both 70 and 100
{\mu}m. We have resolved the dust-producing planetesimal belt of a debris disc
at 100 {\mu}m for the first time. We measure the radial profile and fractional
luminosity of the disc, and compare the values to those of discs around stars
of similar age and/or spectral type, placing this disc in context of other
resolved discs observed by Herschel/DUNES.Comment: 6 pages, 3 figure