IAR   05382
INSTITUTO ARGENTINO DE RADIOASTRONOMIA
Unidad Ejecutora - UE
artículos
Título:
NGC 3503 and its molecular environment
Autor/es:
DURONEA,N.U.; VASQUEZ, J.; CAPPA, C.E. ; CORTI, M.A; ARNAL, E.M.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Lugar: Paris; Año: 2012 vol. 537 p. 149 - 161
ISSN:
0004-6361
Resumen:
Aims: We present a study of the molecular gas and interstellar
dust distribution in the environs of the Hii region NGC 3503 associated
with the open cluster Pis 17 with the aim of investigating the spatial
distribution of the molecular gas linked to the nebula and achieving a
better understanding of the interaction of the nebula and Pis 17 with
their molecular environment. Methods: We based our study on
12CO(1-0) observations of a region of ~0.6° in size
obtained with the 4-m NANTEN telescope, unpublished radio continuum data
at 4800 and 8640 MHz obtained with the ATCA telescope, radio continuum
data at 843 MHz obtained from SUMSS, and available IRAS, MSX,
IRAC-GLIMPSE, and MIPSGAL images. Results: We found a molecular
cloud (Component 1) having a mean velocity of -24.7 km s-1
,compatible with the velocity of the ionized gas, which is associated
with the nebula and its surroundings. Adopting a distance of 2.9
± 0.4 kpc, the total molecular mass yields (7.6 ± 2.1)
× 103Msun and density yields 400 ±
240 cm-3. The radio continuum data confirm the existence of
an electron density gradient in NGC 3503. The IR emission shows a PDR
bordering the higher density regions of the nebula. The spatial
distribution of the CO emission shows that the nebula coincides with a
molecular clump, and the strongest CO emission peak is located close to
the higher electron density region. The more negative velocities of the
molecular gas (about -27 km s-1), are coincident with NGC
3503. Candidate young stellar objects (YSOs) were detected toward the
Hii region, suggesting that embedded star formation may be occurring in
the neighborhood of the nebula. The clear electron density gradient,
along with the spatial distribution of the molecular gas and PAHs in the
region indicates that NGC 3503