TY - JOUR
T1 - VISION - Vienna survey in Orion III.
T2 - Young stellar objects in Orion A
AU - Grossschedl, Josefa Elisabeth
AU - Alves, Joao
AU - Teixeira, Paula S.
AU - Bouy, Herve
AU - Forbrich, Jan
AU - Lada, Charles J.
AU - Meingast, Stefan
AU - Hacar, Alvaro
AU - Ascenso, Joana
AU - Ackerl, Christine
AU - Hasenberger, Birgit
AU - Koehler, Rainer
AU - Kubiak, Karolina
AU - Larreina, Irati
AU - Linhardt, Lorenz
AU - Lombardi, Marco
AU - Moeller, Torsten
N1 - Copyright © ESO 2019
PY - 2019/2/12
Y1 - 2019/2/12
N2 - We have extended and refined the existing young stellar object (YSO)
catalogs for the Orion A molecular cloud, the closest massive
star-forming region to Earth. This updated catalog is driven by the
large spatial coverage (18.3 deg2, ∼950 pc2), seeing limited resolution (∼0.7″), and sensitivity (Ks < 19 mag)
of the ESO-VISTA near-infrared survey of the Orion A cloud (VISION).
Combined with archival mid- to far-infrared data, the VISTA data allow
for a refined and more robust source selection. We estimate that among
previously known protostars and pre-main-sequence stars with disks,
source contamination levels (false positives) are at least ∼6.4% and
∼2.3%, respectively, mostly due to background galaxies and nebulosities.
We identify 274 new YSO candidates using VISTA/Spitzer based
selections within previously analyzed regions, and VISTA/WISE based
selections to add sources in the surroundings, beyond previously
analyzed regions. The WISE selection method recovers about 59% of the
known YSOs in Orion A’s low-mass star-forming part L1641, which shows
what can be achieved by the all-sky WISE survey in combination with deep
near-infrared data in regions without the influence of massive stars.
The new catalog contains 2980 YSOs, which were classified based on the
de-reddened mid-infrared spectral index into 188 protostars, 185
flat-spectrum sources, and 2607 pre-main-sequence stars with
circumstellar disks. We find a statistically significant difference in
the spatial distribution of the three evolutionary classes with respect
to regions of high dust column-density, confirming that flat-spectrum
sources are at a younger evolutionary phase compared to Class IIs, and
are not a sub-sample seen at particular viewing angles.
AB - We have extended and refined the existing young stellar object (YSO)
catalogs for the Orion A molecular cloud, the closest massive
star-forming region to Earth. This updated catalog is driven by the
large spatial coverage (18.3 deg2, ∼950 pc2), seeing limited resolution (∼0.7″), and sensitivity (Ks < 19 mag)
of the ESO-VISTA near-infrared survey of the Orion A cloud (VISION).
Combined with archival mid- to far-infrared data, the VISTA data allow
for a refined and more robust source selection. We estimate that among
previously known protostars and pre-main-sequence stars with disks,
source contamination levels (false positives) are at least ∼6.4% and
∼2.3%, respectively, mostly due to background galaxies and nebulosities.
We identify 274 new YSO candidates using VISTA/Spitzer based
selections within previously analyzed regions, and VISTA/WISE based
selections to add sources in the surroundings, beyond previously
analyzed regions. The WISE selection method recovers about 59% of the
known YSOs in Orion A’s low-mass star-forming part L1641, which shows
what can be achieved by the all-sky WISE survey in combination with deep
near-infrared data in regions without the influence of massive stars.
The new catalog contains 2980 YSOs, which were classified based on the
de-reddened mid-infrared spectral index into 188 protostars, 185
flat-spectrum sources, and 2607 pre-main-sequence stars with
circumstellar disks. We find a statistically significant difference in
the spatial distribution of the three evolutionary classes with respect
to regions of high dust column-density, confirming that flat-spectrum
sources are at a younger evolutionary phase compared to Class IIs, and
are not a sub-sample seen at particular viewing angles.
KW - methods: observational
KW - stars: formation
KW - stars: pre-main sequence
KW - ISM: clouds
KW - infrared: stars
KW - methods: statistical
UR - https://research-portal.st-andrews.ac.uk/en/researchoutput/vision--vienna-survey-in-orion-iii-young-stellar-objects-in-orion-a(663e4394-42b0-4762-a27a-dac61a5fc28e).html
U2 - 10.1051/0004-6361/201832577
DO - 10.1051/0004-6361/201832577
M3 - Article
SN - 1432-0746
VL - 622
SP - 1
EP - 38
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A149
ER -