Opt. spectra of blue MIR objects in LMC Virtual Observatory Resource

Authors
  1. Ishioka R.
  2. Chu Y.-H.
  3. Edmister A.
  4. Gruendl R.A.
  5. Zhang L.
  6. Zhu J.
  7. Published by
    CDS
Abstract

We present low-resolution optical spectra and classifications of 92 blue objects with mid-infrared excesses in the Large Magellanic Cloud. The majority of these objects were selected with the criteria of U-B<0 and V<17 from the potential young stellar object (YSO) candidates in Gruendl & Chu (GC09; 2009, J/ApJS/184/172), which were identified based on Spitzer Infrared Array Camera and Multiband Imaging Photometer for Spitzer observations in conjunction with optical photometry from the Magellanic Clouds Photometric Survey. Many of the sample objects have ambiguous classifications. We examined the properties of these 92 objects using low-resolution optical spectra obtained with the SOAR 4.1m Telescope at Cerro Pachon and the Blanco 4m Telescope at Cerro Tololo Inter-American Observatory, supplemented by available photometric and imaging observations. We estimated the spectral types, temperatures, and luminosities of these objects from the optical to near-IR spectral energy distributions based on the photometric data, and further examined stellar absorption line features in the optical spectra to verify the spectral types. The interstellar/circumstellar environments, assessed from nebular line imaging observations and nebular lines detected in the stellar spectra, further helped constrain the nature of stars. Among these 92 objects, we confirm 42 stars as YSOs, and the remaining 50 objects as protoplanetary nebulae, post-AGB/RGB stars, blue evolved massive stars, stars with dust in vicinity, or uncertain classifications. Our results show that the photometric criteria in GC09 are generally effective in the initial selection of YSO candidates, and the low- resolution spectroscopy combined with environment assessment can be useful to better constrain the classifications and ameliorate most ambiguities.

Keywords
  1. magellanic-clouds
  2. young-stellar-objects
  3. infrared-photometry
  4. visible-astronomy
  5. spectroscopy
  6. two-color-diagrams
  7. absolute-magnitude
  8. interstellar-reddening
  9. stellar-spectral-types
  10. effective-temperature
Bibliographic source Bibcode
2023ApJS..265...18I
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/265/18
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJS/265/18
Document Object Identifer DOI
doi:10.26093/cds/vizier.22650018

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/265/18
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/265/18
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/265/18
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Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/265/18/blue?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/265/18/blue?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/265/18/blue?
IVOA Cone Search SCS
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http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/265/18/tablea1?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/265/18/tablea1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/265/18/tablea1?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/265/18/tablea2?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/265/18/tablea2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/265/18/tablea2?

History

2023-06-16T10:23:38Z
Resource record created
2023-06-16T10:23:38Z
Created
2023-10-17T11:35:17Z
Updated

Contact

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CDS support team
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