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Title: VLT/SINFONI Observations of Spitzer /MIPSGAL 24 μ m Circumstellar Shells: Revealing the Natures of Their Central Sources

Abstract

We present Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared H - and K -band spectra of potential central stars within the inner 8″-by-8″ regions of 55 MIPSGAL “bubbles” (MBs), sub-arcminute circumstellar shells discovered in the mid-IR survey of the Galactic plane with Spitzer /MIPS. At magnitudes brighter than 15, we detect a total of 230 stars in the K band and 179 stars in the H band. We spectrally identify 145 stars in all but three MBs, with average magnitudes of 13.8 and 12.7 respectively, using spectral libraries and previous studies of near-IR stellar spectra. We also use tabulated intrinsic stellar magnitudes and colors to derive distances and extinction values, and to better constrain the classifications of the stars. We reliably identify the central sources for 21 of the 55 MBs, which we classify as follows: one Wolf–Rayet, three luminous blue variable candidates, four early-type (O to F), and 15 late-type (G to M) stars. The 21 central sources are, on average, one magnitude fainter than these in the most recent study of MBs, and we notice a significant drop in the fraction of massive star candidates. For the 34 remaining MBs in our sample, wemore » are unable to identify the central sources due to confusion, low spectroscopic signal-to-noise ratio, and/or lack of detections in the images near the centers of the bubbles. We discuss how our findings compare with previous studies and support the trend, for the most part, between the shells’ morphologies in the mid-IR and central sources spectral types.« less

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. Physics and Astronomy Department, University of Hawaii Hilo, 200 W Kawili Street, Hilo, HI 96720 (United States)
  2. Canada–France–Hawaii Telescope Corporation, 65-1238 Mamalahoa Highway, Kamuela, HI 96743 (United States)
  3. Space Telescope Science Institue, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  4. Infrared Processing Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
  5. INAF-Osservatorio Astrofisico di Catania, Via Santa Sofia 78, I-95123 Catania (Italy)
Publication Date:
OSTI Identifier:
22663742
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 3; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CLASSIFICATION; COMPARATIVE EVALUATIONS; DETECTION; DISTANCE; GIANT STARS; IMAGES; MILKY WAY; MORPHOLOGY; NEAR INFRARED RADIATION; NOISE; POTENTIALS; SIGNAL-TO-NOISE RATIO; TELESCOPES; WOLF-RAYET STARS

Citation Formats

Silva, K. M., Flagey, N., Noriega-Crespo, A., Carey, S., and Ingallinera, A., E-mail: silvakm@hawaii.edu. VLT/SINFONI Observations of Spitzer /MIPSGAL 24 μ m Circumstellar Shells: Revealing the Natures of Their Central Sources. United States: N. p., 2017. Web. doi:10.3847/1538-3881/153/3/115.
Silva, K. M., Flagey, N., Noriega-Crespo, A., Carey, S., & Ingallinera, A., E-mail: silvakm@hawaii.edu. VLT/SINFONI Observations of Spitzer /MIPSGAL 24 μ m Circumstellar Shells: Revealing the Natures of Their Central Sources. United States. doi:10.3847/1538-3881/153/3/115.
Silva, K. M., Flagey, N., Noriega-Crespo, A., Carey, S., and Ingallinera, A., E-mail: silvakm@hawaii.edu. Wed . "VLT/SINFONI Observations of Spitzer /MIPSGAL 24 μ m Circumstellar Shells: Revealing the Natures of Their Central Sources". United States. doi:10.3847/1538-3881/153/3/115.
@article{osti_22663742,
title = {VLT/SINFONI Observations of Spitzer /MIPSGAL 24 μ m Circumstellar Shells: Revealing the Natures of Their Central Sources},
author = {Silva, K. M. and Flagey, N. and Noriega-Crespo, A. and Carey, S. and Ingallinera, A., E-mail: silvakm@hawaii.edu},
abstractNote = {We present Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared H - and K -band spectra of potential central stars within the inner 8″-by-8″ regions of 55 MIPSGAL “bubbles” (MBs), sub-arcminute circumstellar shells discovered in the mid-IR survey of the Galactic plane with Spitzer /MIPS. At magnitudes brighter than 15, we detect a total of 230 stars in the K band and 179 stars in the H band. We spectrally identify 145 stars in all but three MBs, with average magnitudes of 13.8 and 12.7 respectively, using spectral libraries and previous studies of near-IR stellar spectra. We also use tabulated intrinsic stellar magnitudes and colors to derive distances and extinction values, and to better constrain the classifications of the stars. We reliably identify the central sources for 21 of the 55 MBs, which we classify as follows: one Wolf–Rayet, three luminous blue variable candidates, four early-type (O to F), and 15 late-type (G to M) stars. The 21 central sources are, on average, one magnitude fainter than these in the most recent study of MBs, and we notice a significant drop in the fraction of massive star candidates. For the 34 remaining MBs in our sample, we are unable to identify the central sources due to confusion, low spectroscopic signal-to-noise ratio, and/or lack of detections in the images near the centers of the bubbles. We discuss how our findings compare with previous studies and support the trend, for the most part, between the shells’ morphologies in the mid-IR and central sources spectral types.},
doi = {10.3847/1538-3881/153/3/115},
journal = {Astronomical Journal (Online)},
number = 3,
volume = 153,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}