A high-resolution spectropolarimetric survey of Herbig Ae/Be stars - I. observations and measurements

Alecian, E. and Wade, G. A. and Catala, C. and Grunhut, J. H. and Landstreet, J. D. and Bagnulo, S. and Bohm, T. and Folsom, C. P. and Marsden, S. and Waite, I. (2013) A high-resolution spectropolarimetric survey of Herbig Ae/Be stars - I. observations and measurements. Monthly Notices of the Royal Astronomical Society , 429 (2). pp. 1001-1026. ISSN 0035-8711

Abstract

This is the first in a series of papers in which we describe and report the analysis of a large survey of Herbig Ae/Be stars in circular spectropolarimetry. Using the ESPaDOnS and Narval high-resolution spectropolarimeters at the Canada-France-Hawaii and Bernard Lyot Telescopes, respectively, we have acquired 132 circularly polarized spectra of 70 Herbig Ae/Be stars and Herbig candidates. The large majority of these spectra are characterized by a resolving power of about 65 000, and a spectral coverage from about 3700Å to 1 μm. The peak signal-to-noise ratio per CCD pixel ranges from below 100 (for the faintest targets) to over 1000 (for the brightest). The observations were acquired with the primary aim of searching for magnetic fields in these objects. However, our spectra are suitable for a variety of other important measurements, including rotational properties, variability, binarity, chemical abundances, circumstellar environment conditions and structure, etc. In this paper, we describe the sample selection, the observations and their reduction, and the measurements that will comprise the basis of much of our following analysis. We describe the determination of fundamental parameters for each target. We detail the least-squares deconvolution (LSD) that we have applied to each of our spectra, including the selection, editing and tuning of the LSD line masks. We describe the fitting of the LSD Stokes I profiles using a multicomponent model that yields the rotationally broadened photospheric profile (providing the projected rotational velocity and radial velocity for each observation) as well as circumstellar emission and absorption components. Finally, we diagnose the longitudinal Zeeman effect via the measured circular polarization, and report the longitudinal magnetic field and Stokes V Zeeman signature detection probability. As an appendix, we provide a detailed review of each star observed.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2012 The Authors. All rights are reserved and no materials may be copied, modified, published, broadcast or otherwise distributed without the prior written permission of the publisher.
Faculty / Department / School: Historic - Faculty of Sciences - No Department
Date Deposited: 19 Sep 2013 00:07
Last Modified: 14 Jul 2014 06:38
Uncontrolled Keywords: binaries; early-type stars; magnetic field; pre-main-sequence; spectroscopic
Fields of Research : 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
02 Physical Sciences > 0201 Astronomical and Space Sciences > 020102 Astronomical and Space Instrumentation
02 Physical Sciences > 0205 Optical Physics > 020503 Nonlinear Optics and Spectroscopy
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
Identification Number or DOI: 10.1093/mnras/sts383
URI: http://eprints.usq.edu.au/id/eprint/23793

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