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Title: Trigonometric distance and proper motion of IRAS 20056+3350: a massive star-forming region on the solar circle

We report our measurement of the trigonometric distance and proper motion of IRAS 20056+3350, obtained from the annual parallax of H{sub 2}O masers. Our distance of D=4.69{sub −0.51}{sup +0.65} kpc, which is 2.8 times larger than the near kinematic distance adopted in the literature, places IRAS 20056+3350 at the leading tip of the Local arm and proximal to the solar circle. Using our distance, we reevaluate past observations to reveal IRAS 20056+3350 as a site of massive star formation at a young stage of evolution. This result is consistent with the spectral energy distribution of the source evaluated with published photometric data from UKIDSS, WISE, AKARI, IRAS, and the submillimeter continuum. Both analytical approaches reveal the luminosity of the region to be 2.4 × 10{sup 4} L {sub ☉}, and suggest that IRAS 20056+3350 is forming an embedded star of ≥16 M {sub ☉}. We estimated the proper motion of IRAS 20056+3350 to be (μ{sub α}cos δ, μ{sub δ}) = (–2.62 ± 0.33, –5.65 ± 0.52) mas yr{sup –1} from the group motion of H{sub 2}O masers, and use our results to estimate the angular velocity of Galactic rotation at the Galactocentric distance of the Sun, Ω{sub 0} = 29.75more » ± 2.29 km s{sup –1} kpc{sup –1}, which is consistent with the values obtained for other tangent point and solar circle objects.« less
Authors:
; ; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Kôrimoto, Kagoshima, Kagoshima 890-0065 (Japan)
  2. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  3. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  4. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-12 Hoshi-ga-oka, Mizusawa-ku, Oshu, Iwate 023-0861 (Japan)
Publication Date:
OSTI Identifier:
22370043
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 797; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR VELOCITY; DISTANCE; ENERGY SPECTRA; GALAXIES; LUMINOSITY; MASERS; PROPER MOTION; ROTATION; STAR EVOLUTION; SUN; WATER