Bibcode
Guarcello, M. G.; Drake, J. J.; Wright, N. J.; García-Alvarez, D.; Kraemer, K. E.
Bibliographical reference
The Astrophysical Journal, Volume 793, Issue 1, article id. 56, 14 pp. (2014).
Advertised on:
9
2014
Journal
Citations
12
Refereed citations
11
Description
Cygnus OB2 is the most massive association within 2 kpc from the Sun,
hosting hundreds of massive stars, thousands of young low mass members,
and some sights of active star formation in the surrounding cloud.
Recently, 10 photoevaporating proplyd-like objects with tadpole-shaped
morphology were discovered in the outskirts of the OB association,
approximately 6-14 pc away from its center. The classification of these
objects is ambiguous, being either evaporating residuals of the parental
cloud that are hosting a protostar inside or disk-bearing stars with an
evaporating disk, such as the evaporating proplyds observed in the
Trapezium Cluster in Orion. In this paper, we present a study based on
low-resolution optical spectroscopic observations made with the Optical
System for Imaging and low Resolution Integrated Spectroscopy, mounted
on the 10.4 m Gran Telescopio CANARIAS, of two of these protostars. The
spectrum of one of the objects shows evidence of accretion but not of
outflows. In the latter object, the spectra show several emission lines
indicating the presence of an actively accreting disk with outflow. We
present estimates of the mass loss rate and the accretion rate from the
disk, showing that the former exceeds the latter as observed in other
known objects with evaporating disks. We also show evidence of a strong
variability in the integrated flux observed in these objects as well as
in the accretion and outflow diagnostics.
Related projects
Chemical Abundances in Stars
Stellar spectroscopy allows us to determine the properties and chemical compositions of stars. From this information for stars of different ages in the Milky Way, it is possible to reconstruct the chemical evolution of the Galaxy, as well as the origin of the elements heavier than boron, created mainly in stellar interiors. It is also possible to
Carlos
Allende Prieto