CaltechAUTHORS
Published October 2, 2001 | Version Published + Submitted
Journal Article Open

Optical spectroscopy of isolated planetary mass objects in the σ Orionis cluster

Creators

  • 1. ROR icon Autonomous University of Madrid
  • 2. ROR icon Max Planck Institute for Astronomy
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon Instituto de Astrofísica de Canarias
  • 5. ROR icon Spanish National Research Council
  • 6. ROR icon University of Hawaii at Manoa

Abstract

We have obtained low resolution optical spectra of 15 isolated planetary mass objects (IPMOs) in the σ Orionis cluster, and derived spectral types by comparison with nearby M and L dwarfs. The spectral types are in the range late M -mid L, in agreement with our expectations based on colors and magnitudes for bona fide members. Therefore, most of these objects have masses below the deuterium burning limit. About 2/3 show Hα in emission at our spectral resolution. From our spectroscopic and photometric data, we infer that three IPMOs in this sample may be binaries with components of similar masses. These results confirm that the substellar mass function of the σ Orionis cluster, in the form dN/dM, keeps rising in the planetary domain.

Additional Information

© 2001 ESO. Received: 29 May 2001. Accepted: 15 August 2001. We thanks the ESO staff at Paranal Observatory. The referee, G. Chabrier, has helped to improve the original version with his comments and suggestions. Partial financial support was provided by the Spanish DGES project PB98-0531-C02-02 and CICYT grant ESP98-1339-CO2.

Attached Files

Published - aade291.pdf

Submitted - 0108249.pdf

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Additional details

Additional titles

Alternative title
Optical spectroscopy of isolated planetary mass objects in the sigma Orionis cluster

Identifiers

Eprint ID
85167
Resolver ID
CaltechAUTHORS:20180307-084140419

Related works

Describes
https://arxiv.org/abs/astro-ph/0108249 (URL)

Funding

Direcção-Geral do Ensino Superior (DGES)
PB98-0531-C02-02
Comisión Interministerial de Ciencia y Tecnología (CICYT)
ESP98-1339-CO2

Dates

Created
2018-03-07
Created from EPrint's datestamp field
Updated
2021-11-15
Created from EPrint's last_modified field