A MOLECULAR SPIRAL ARM IN THE FAR OUTER GALAXY
Journal Article
·
· Astrophysical Journal Letters
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
We have identified a spiral arm lying beyond the Outer Arm in the first Galactic quadrant {approx}15 kpc from the Galactic center. After tracing the arm in existing 21 cm surveys, we searched for molecular gas using the CfA 1.2 m telescope and detected CO at 10 of 220 positions. The detections are distributed along the arm from l = 13{sup 0}, v = -21 km s{sup -1} to l = 55{sup 0}, v = -84 km s{sup -1} and coincide with most of the main H I concentrations. One of the detections was fully mapped to reveal a large molecular cloud with a radius of 47 pc and a molecular mass of {approx}50,000 M{sub sun}. At a mean distance of 21 kpc, the molecular gas in this arm is the most distant yet detected in the Milky Way. The new arm appears to be the continuation of the Scutum-Centaurus Arm in the outer Galaxy, as a symmetric counterpart of the nearby Perseus Arm.
- OSTI ID:
- 21562605
- Journal Information:
- Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 734; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
A POSSIBLE EXTENSION OF THE SCUTUM-CENTAURUS ARM INTO THE OUTER SECOND QUADRANT
Molecular clouds and galactic spiral structure
AN OUTER ARM IN THE SECOND GALACTIC QUADRANT: STRUCTURE
Journal Article
·
Fri Jan 09 23:00:00 EST 2015
· Astrophysical Journal Letters
·
OSTI ID:22364693
Molecular clouds and galactic spiral structure
Journal Article
·
Tue Jul 15 00:00:00 EDT 1980
· Astrophys. J., Lett. Ed.; (United States)
·
OSTI ID:7054519
AN OUTER ARM IN THE SECOND GALACTIC QUADRANT: STRUCTURE
Journal Article
·
Sun May 01 00:00:00 EDT 2016
· Astrophysical Journal, Supplement Series
·
OSTI ID:22661078