308 research outputs found
Young stars in the Camelopardalis dust and molecular clouds. VI. YSOs verified by Spitzer and AKARI infrared photometry
Using photometric data of infrared surveys, young stellar object (YSO) status
is verified for 141 objects selected in our previous papers in the Cassiopeia
and Camelopardalis segment of the Milky Way bounded by Galactic coordinates (l,
b) = (132--158 deg, p/m 12 deg). The area includes the known star-forming
regions in the emission nebulae W3, W4 and W5 and the massive YSO AFGL 490.
Spectral energy distribution (SED) curves between 700 nm and 160 microns,
constructed from the GSC2, 2MASS, IRAS, MSX, Spitzer and AKARI data, are used
to estimate the evolutionary stages of these stars. We confirm the YSO status
for most of the objects. If all of the investigated objects were YSOs, 45 % of
them should belong to Class I, 41 % to class II and 14 % to Class III. However,
SEDs of some of these objects can be affected by nearby extended infrared
sources, like compact H II regions, infrared clusters or dusty galaxies.Comment: 33 pages, 2 figure
Disentangling the Environment of the FU Orionis Candidate HBC 722 with Herschel
We analyze the submillimeter emission surrounding the new FU Orionis-type
object, HBC 722. We present the first epoch of observations of the active
environs of HBC 722, with imaging and spectroscopy from PACS, SPIRE, and HIFI
aboard the Herschel Space Observatory, as well as CO J= 2-1 and 350 um imaging
(SHARC-II) with the Caltech Submillimeter Observatory. The primary source of
submillimeter continuum emission in the region -- 2MASS 20581767+4353310 -- is
located 16\arcsec south-southeast of the optical flaring source while the
optical and near-IR emission is dominated by HBC 722. A bipolar outflow extends
over HBC 722; the most likely driver is the submillimeter source. We detect
warm (100 K) and hot (246 K) CO emission in the surrounding region, evidence of
outflow-driven heating in the vicinity. The region around HBC 722 itself shows
little evidence of heating driven by the new outbursting source itself.Comment: Accepted by ApJL 10 March 2011; 14 pages, 4 figures, 1 tabl
- …