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Title: THE FIRST DISTANCE CONSTRAINT ON THE RENEGADE HIGH-VELOCITY CLOUD COMPLEX WD

Abstract

We present medium-resolution, near-ultraviolet Very Large Telescope/FLAMES observations of the star USNO-A0600-15865535. We adapt a standard method of stellar typing to our measurement of the shape of the Balmer ϵ absorption line to demonstrate that USNO-A0600-15865535 is a blue horizontal branch star, residing in the lower stellar halo at a distance of 4.4 kpc from the Sun. We measure the H and K lines of singly ionized calcium and find two isolated velocity components, one originating in the disk, and one associated with the high-velocity cloud complex WD. This detection demonstrated that complex WD is closer than ∼4.4 kpc and is the first distance constraint on the +100 km s{sup −1} Galactic complex of clouds. We find that complex WD is not in corotation with the Galactic disk, which has been assumed for decades. We examine a number of scenarios and find that the most likely scenario is that complex WD was ejected from the solar neighborhood and is only a few kiloparsecs from the Sun.

Authors:
; ;  [1];  [2];  [3];  [4]
  1. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  2. MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
  3. Institute of Astronomy, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium)
  4. Department of Astronomy, Columbia University, New York, NY 10027 (United States)
Publication Date:
OSTI Identifier:
22654223
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 828; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ATOMS; CALCIUM; CLOUDS; DETECTION; EVOLUTION; FLAMES; GALAXIES; LIMITING VALUES; RESOLUTION; SUN; TELESCOPES; ULTRAVIOLET RADIATION; VELOCITY

Citation Formats

Peek, J. E. G., Roman-Duval, Julia, Tumlinson, Jason, Bordoloi, Rongmon, Sana, Hugues, and Zheng, Yong. THE FIRST DISTANCE CONSTRAINT ON THE RENEGADE HIGH-VELOCITY CLOUD COMPLEX WD. United States: N. p., 2016. Web. doi:10.3847/2041-8205/828/2/L20.
Peek, J. E. G., Roman-Duval, Julia, Tumlinson, Jason, Bordoloi, Rongmon, Sana, Hugues, & Zheng, Yong. THE FIRST DISTANCE CONSTRAINT ON THE RENEGADE HIGH-VELOCITY CLOUD COMPLEX WD. United States. doi:10.3847/2041-8205/828/2/L20.
Peek, J. E. G., Roman-Duval, Julia, Tumlinson, Jason, Bordoloi, Rongmon, Sana, Hugues, and Zheng, Yong. 2016. "THE FIRST DISTANCE CONSTRAINT ON THE RENEGADE HIGH-VELOCITY CLOUD COMPLEX WD". United States. doi:10.3847/2041-8205/828/2/L20.
@article{osti_22654223,
title = {THE FIRST DISTANCE CONSTRAINT ON THE RENEGADE HIGH-VELOCITY CLOUD COMPLEX WD},
author = {Peek, J. E. G. and Roman-Duval, Julia and Tumlinson, Jason and Bordoloi, Rongmon and Sana, Hugues and Zheng, Yong},
abstractNote = {We present medium-resolution, near-ultraviolet Very Large Telescope/FLAMES observations of the star USNO-A0600-15865535. We adapt a standard method of stellar typing to our measurement of the shape of the Balmer ϵ absorption line to demonstrate that USNO-A0600-15865535 is a blue horizontal branch star, residing in the lower stellar halo at a distance of 4.4 kpc from the Sun. We measure the H and K lines of singly ionized calcium and find two isolated velocity components, one originating in the disk, and one associated with the high-velocity cloud complex WD. This detection demonstrated that complex WD is closer than ∼4.4 kpc and is the first distance constraint on the +100 km s{sup −1} Galactic complex of clouds. We find that complex WD is not in corotation with the Galactic disk, which has been assumed for decades. We examine a number of scenarios and find that the most likely scenario is that complex WD was ejected from the solar neighborhood and is only a few kiloparsecs from the Sun.},
doi = {10.3847/2041-8205/828/2/L20},
journal = {Astrophysical Journal Letters},
number = 2,
volume = 828,
place = {United States},
year = 2016,
month = 9
}
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