ORIGIN OF THE DIFFUSE, FAR ULTRAVIOLET EMISSION IN THE INTERARM REGIONS OF M101

Journal Article · Mon Jul 20 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/808/1/76· OSTI ID:22522133

Crocker, Alison F.; Chandar, Rupali ^[1]; Calzetti, Daniela ^[2]; Holwerda, Benne Willem ^[3]; Leitherer, Claus ^[4]; Popescu, Cristina ^[5]

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1. Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)
2. Department of Astrophysics, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States)
3. University of Leiden, Leiden Observatory, Niels Bohrweg 4, NL-2333, Leiden (Netherlands)
4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
5. Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

We present images from the Solar Blind Channel on the Hubble Space Telescope that resolve hundreds of far-ultraviolet (FUV) emitting stars in two ∼1 kpc{sup 2} interarm regions of the grand-design spiral M101. The luminosity functions of these stars are compared with predicted distributions from simple star formation histories, and are best reproduced when the star formation rate has recently declined (past 10–50 Myr). This pattern is consistent with stars forming within spiral arms and then streaming into the interarm regions. We measure the diffuse FUV surface brightness after subtracting all of the detected stars, clusters, and background galaxies. A residual flux is found for both regions, which can be explained by a mix of stars below our detection limit and scattered FUV light. The amount of scattered light required is much larger for the region immediately adjacent to a spiral arm, a bright source of FUV photons.

• OSTI ID: 22522133
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 808; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
COMPARATIVE EVALUATIONS
COSMIC DUST
COSMIC PHOTONS
FAR ULTRAVIOLET RADIATION
GALAXIES
IMAGES
LUMINOSITY
PHOTON EMISSION
SCATTERING
SENSITIVITY
SPACE
STAR CLUSTERS
STAR EVOLUTION
STARS
TELESCOPES
VISIBLE RADIATION