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Title: CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION

Abstract

Interarm star formation contributes significantly to a galaxy’s star formation budget and provides an opportunity to study stellar birthplaces unperturbed by spiral arm dynamics. Using optical integral field spectroscopy of the nearby galaxy NGC 628 with VLT/MUSE, we construct H α maps including detailed corrections for dust extinction and stellar absorption to identify 391 H ii regions at 35 pc resolution over 12 kpc{sup 2}. Using tracers sensitive to the underlying gravitational potential, we associate H ii regions with either arm (271) or interarm (120) environments. Using our full spectral coverage of each region, we find that most physical properties (luminosity, size, metallicity, ionization parameter) of H ii regions are independent of environment. We calculate the fraction of H α luminosity due to the background of diffuse ionized gas (DIG) contaminating each H ii region, and find the DIG surface brightness to be higher within H ii regions than in the surroundings, and slightly higher within arm H ii regions. Use of the temperature-sensitive [S ii]/H α line ratio instead of the H α surface brightness to identify the boundaries of H ii regions does not change this result. Using the dust attenuation as a tracer of the gas, wemore » find depletion times consistent with previous work (2 × 10{sup 9} yr) with no differences between the arm and interarm, but this is very sensitive to the DIG correction. Unlike molecular clouds, which can be dynamically affected by the galactic environment, we see fairly consistent properties of H ii regions in both arm and interarm environments. This suggests either a difference in star formation and feedback in arms or a decoupling of dense star-forming clumps from the more extended surrounding molecular gas.« less

Authors:
; ;  [1];  [2];  [3];  [4];  [5]
  1. Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  2. Departamento de Astronomía, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago (Chile)
  3. Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)
  4. Department of Astronomy, The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden)
  5. CNRS, IRAP, 9 Av. du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France)
Publication Date:
OSTI Identifier:
22667524
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 827; 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; ATTENUATION; BALMER LINES; BRIGHTNESS; CLOUDS; CORRECTIONS; COSMIC DUST; DECOUPLING; FEEDBACK; GALAXIES; IONIZATION; LUMINOSITY; METALLICITY; RESOLUTION; SPECTROSCOPY; STARS; SURFACES

Citation Formats

Kreckel, K., Schinnerer, E., Meidt, S., Blanc, G. A., Groves, B., Adamo, A., and Hughes, A., E-mail: kreckel@mpia.de. CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION. United States: N. p., 2016. Web. doi:10.3847/0004-637X/827/2/103.
Kreckel, K., Schinnerer, E., Meidt, S., Blanc, G. A., Groves, B., Adamo, A., & Hughes, A., E-mail: kreckel@mpia.de. CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION. United States. doi:10.3847/0004-637X/827/2/103.
Kreckel, K., Schinnerer, E., Meidt, S., Blanc, G. A., Groves, B., Adamo, A., and Hughes, A., E-mail: kreckel@mpia.de. Sat . "CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION". United States. doi:10.3847/0004-637X/827/2/103.
@article{osti_22667524,
title = {CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION},
author = {Kreckel, K. and Schinnerer, E. and Meidt, S. and Blanc, G. A. and Groves, B. and Adamo, A. and Hughes, A., E-mail: kreckel@mpia.de},
abstractNote = {Interarm star formation contributes significantly to a galaxy’s star formation budget and provides an opportunity to study stellar birthplaces unperturbed by spiral arm dynamics. Using optical integral field spectroscopy of the nearby galaxy NGC 628 with VLT/MUSE, we construct H α maps including detailed corrections for dust extinction and stellar absorption to identify 391 H ii regions at 35 pc resolution over 12 kpc{sup 2}. Using tracers sensitive to the underlying gravitational potential, we associate H ii regions with either arm (271) or interarm (120) environments. Using our full spectral coverage of each region, we find that most physical properties (luminosity, size, metallicity, ionization parameter) of H ii regions are independent of environment. We calculate the fraction of H α luminosity due to the background of diffuse ionized gas (DIG) contaminating each H ii region, and find the DIG surface brightness to be higher within H ii regions than in the surroundings, and slightly higher within arm H ii regions. Use of the temperature-sensitive [S ii]/H α line ratio instead of the H α surface brightness to identify the boundaries of H ii regions does not change this result. Using the dust attenuation as a tracer of the gas, we find depletion times consistent with previous work (2 × 10{sup 9} yr) with no differences between the arm and interarm, but this is very sensitive to the DIG correction. Unlike molecular clouds, which can be dynamically affected by the galactic environment, we see fairly consistent properties of H ii regions in both arm and interarm environments. This suggests either a difference in star formation and feedback in arms or a decoupling of dense star-forming clumps from the more extended surrounding molecular gas.},
doi = {10.3847/0004-637X/827/2/103},
journal = {Astrophysical Journal},
number = 2,
volume = 827,
place = {United States},
year = {Sat Aug 20 00:00:00 EDT 2016},
month = {Sat Aug 20 00:00:00 EDT 2016}
}