| Type |
Journal Article |
| Names |
Rachael L. Beaton, David Martínez-Delgado, Steven R. Majewski, Elena D'Onghia, Stefano Zibetti, R. Jay Gabany, Kelsey E. Johnson, Michael Blanton, Anne Verbiscer |
| Publication |
The Astrophysical Journal |
| Volume |
790 |
| Issue |
2 |
| Pages |
117 |
| Journal Abbreviation |
The Astrophysical Journal |
| Date |
August 1, 2014 |
| DOI |
10.1088/0004-637X/790/2/117 |
| ISSN |
0004-637X |
| URL |
http://adsabs.org/2014ApJ.790.117B |
| Library Catalog |
adslabs.org |
| Abstract |
We have identified a low surface brightness stellar stream from visual
inspection of Sloan Digital Sky Survey (SDSS) imaging for the edge-on,
spiral galaxy NGC 5387. An optically blue overdensity coincident with
the stream intersection with the NGC 5387 disk was also identified in
SDSS and in the Galaxy Evolution Explorer Deep Imaging Survey
contributing 38% of the total far-UV integrated flux from NGC 5387.
Deeper optical imaging was acquired with the Vatican Advanced Technology
Telescope that confirmed the presence of both features. The stellar
stream is red in color, (B - V) = 0.7, has a stellar mass of 6
× 108 M ⊙, which implies a 1:50 merger
ratio, has a circular radius, R circ ~ 11.7 kpc, formed in
~240 Myr, and the progenitor had a total mass of ~4 ×
1010 M ⊙. Spectroscopy from LBT+MODS1 was
used to determine that the blue overdensity is at the same redshift as
NGC 5387, consists of young stellar populations (~10 Myr), is metal-poor
(12 + log (O/H) = 8.03), and is forming stars at an enhanced rate (~1-3
M ⊙ yr-1). The most likely
interpretations are that the blue overdensity is (1) a region of
enhanced star formation in the outer disk of NGC 5387 induced by the
minor accretion event or (2) the progenitor of the stellar stream
experiencing enhanced star formation. Additional exploration of these
scenarios is presented in a companion paper.
Based on observations with the VATT: the Alice P. Lennon Telescope and
the Thomas J. Bannan Astrophysics Facility. |
| Tags |
GALAXIES: EVOLUTION, Galaxies: Dwarf, Galaxies: General, galaxies: individual: NGC 5387, galaxies: star formation |