198 7Apjs. . .65. .45 9T the Astrophysical Journal

9T The Astrophysical Journal Supplement Series, 65:459-483, 1987 November .45 © 1987. The American Astronomical Society. All rights reserved. Printed in U.S.A. .65. 7ApJS. AN ATLAS OF OPTICAL SPECTROPHOTOMETRY OF WOLF-RAYET CARBON 198 AND OXYGEN STARS Ana V. Torres1 NASA/Goddard Space Flight Center, Laboratory for Astronomy and Solar Physics AND Philip Massey2 Kitt Peak National Observatory, National Optical Astronomy Observatories Received 1987 February 2; accepted 1987 April 28 ABSTRACT The atlas contams a homogeneous set of optical spectrophotometric observations (3300-7300 A) at moderate resolution ( ~ 10 À) of almost all WC and WO stars in the Galaxy, the LMC, and the SMC. The data are presented in the form of spectral tracings (in magnitude units) arranged by subtype, with no correction for interstellar reddening. A montage of prototype stars of each spectral class is also shown. Comprehensive line identifications are given for the optical lines of WC and WO spectra, with major contributions tabulated and unidentified lines noted. Fluxes of individual stars can be obtained from the Astronomical Data Center at NASA/Goddard Space Flight Center. Subject headings: line identifications — spectrophotometry — stars: Wolf-Rayet I. INTRODUCTION line profiles of the nitrogen sequence (WN). Vreux, Denne- The spectra of Wolf-Rayet (W-R) stars are very rich in feld, and Andrillat (1983) have published a catalog of near- strong, broad emission lines arising from various ionization infrared spectra of southern Galactic W-R stars. In addition, and excitation levels of nitrogen and helium (WN stars), or Smith and Wilhs (1983) have done UV and visible spectro- carbon, helium, and oxygen (WC and WO stars), as well as photometry of several W-R stars in the Large Magellanic from the lesser contributions of other ions. These elements are Cloud (LMÇ), and Lundström and Stenholm (1984) present all the products of nuclear burning; by the time a massive star optical spectroscopy of southern W-R stars. All these studies reaches the W-R stage, little hydrogen is left (see Abbott and are complemented by the Sixth Catalogue of Galactic W-R Conti 1987 for a recent review). The stellar winds of W-R Stars (van der Hucht et al 1981, hereafter the Catalogue). stars are some of the strongest known, as evidenced from the Most of the above studies involve only prototype stars of a line breadths and from the P Cygni-type profiles in their given subtype, or a few stars of the same subtypes. However, spectra. The stellar wind terminal velocities range from ~ 1000 the heterogeneity in line strengths within a given subtype to 5000 km s-1, and their mass-loss rates are of the order of (more pronounced in WN than in WC stars; see Conti 1982), 5 1 10“ Mq yr“ (Abbott et al. 1986). in intrinsic colors (Massey 1984) and in terminal velocities Our knowledge of W-R stars is based primarily on informa- (Torres, Conti, and Massey 1986), has been demonstrated for tion gleaned from their spectral characteristics, since their W-R stars. Therefore we have decided to compile a homoge- effective temperatures, bolometric luminosities, and masses neous set of spectrophotometric observations at moderate are notoriously hard to determine directly (Abbott and Conti resolution ( ~ 10 Á) of WC stars, covering all the WC sub- 1987). During the last five years a number of spectroscopic types and almost all known WC and WO stars in the Galaxy and spectrophotometric studies have been done in various and the LMC. wavelength regimes, including the recent atlas of ultraviolet The purpose of this atlas is to help study the following (UV) spectra presented by Wilhs et al. (1986). Because of its problems: high resolution it is appropriate for studies of line transfer in 1. Evolution of W-R stars. Line identifications are indis- W-R atmospheres. Similarly, high-resolution optical work can pensable in order to know the chemical composition and be found in the Smith and Kuhi (1981) atlas, which discusses therefore the evolutionary status of WC stars. 2. Heterogeneity of spectral properties within a given subtype. 3. Interstellar extinction toward WC and WO stars, especially the ones in OB clusters or associations. Spectro- National Research Council Research Associate. 2 Visiting Astronomer, Cerro Tololo Inter-American Observatory, photometry down to 1100 A taken with the International National Optical Astronomy Observatories, which is operated by Asso- Ultraviolet Explorer can be used as a complement to the ciated Universities for Research in Astronomy, Inc., under contract to the observations in this atlas (e.g., Garmany, Massey, and National Science Foundation. Conti 1984). © American Astronomical Society • Provided by the NASA Astrophysics Data System 9T TABLEI .45 WC and WO Stars Included in the Atlas .65. b . Other Name Instrument Type“ Star Comments WO + Sk 188 Sand 1, AB 8 SIT Incorrect wavelength scale for red observation BR 93 Sand 2, FD 73 SIT Air mass of red observation -1.54 7ApJS. WR 72 Sand 3, NS 1 SIT Planetary nucleus 198 WR 102 Sand 4 1RS, SIT Air mass of red observation =1.98 WR 142 Sand 5, ST 3 1RS Nonphotometric WC4. BR 7 HD 32125 SIT BR 8 HD 32257 SIT BR 10 HD 32402 SIT Other star in slit; blue includes measurements at air masses =1.53 + BR 28 HD 36156 SIT Blue continuum shape may be wrong + BR 31 HD 36402 SIT Incorrect wavelength scale for red observation + BR32 HD 36521 SIT Blue continuum shape may be wrong BR 43 HD 37026 SIT X4650 is saturated in the blue observation; incorrect wavelength scale for red observation BR 50 HD 37680 SIT Incorrect wavelength scale for red observation; X4650 is saturated in the red observation BR 74 HDE 269888 SIT 1.51 < air mass <1.58 WR 19 LS 3 SIT WR 38 MS 8 SIT Other star in slit WR 144 MR 110 1RS No blue observation WC5. WR4 HD 16523 1RS +WR9 HD 63099 SIT WR 17 HD 88500 SIT WR 33 HD 95435 SIT WR 52 HD 115473 SIT WR 111 HD 165763 1RS Air mass = 1.86 WR 114 HD 169010 1RS, SIT Air mass of 1RS red observation = 1.56 WR 126 ST 2 1RS X < 4400 A is nonphotometric WR 143 HD 195177 1RS X < 4400 A is nonphotometric WR 150 ST 5 1RS Blue is nonphotometric WC6. + BR 22 WS 16 SIT WR 5 HD 17638 1RS WR 13 MR 15 SIT WR 14 HD 76536 SIT WR 15 HD 79573 SIT WR 23 HD 92809 SIT + WR 27 LS 4 SIT + WR 30 HD 94305 SIT Red is nonphotometric WR 39 MS 9 SIT No blue observation; faint star just off slit + WR 50 MR 44 SIT Red is nonphotometric WR 132 HD 190002 1RS WR 154 HD 213049 1RS WC7. + WR 42 HD 97152 SIT No red observation WR 56 LS 8 SIT Blue is nonphotometric WR 57 HD 119078 SIT WR 68 BS 4 SIT + WR 86 HD 156327 SIT + WR 93 HD 157504 SIT WR 125 MR 93 1RS + WR 137 HD 192641 1RS + WR 140 HD 193793 1RS Red is nonphotometric WC8. WR 53 HD 117297 SIT WR 60 HD 121194 SIT + WR 70 HD 137603 SIT WR 77 MR 62 SIT + WR 113 HD 168206, CV Ser 1RS Ar mass >1.5 WR 135 HD 192103 1RS WC9. WR 59 LSS 3164 SIT No blue observation WR 65 WRA 1297 SIT WR 69 HD 136488 SIT WR 73 NS 3 SIT WR 80 WRA 1581 SIT WR 81 MR 66 SIT © American Astronomical Society Provided by the NASA Astrophysics Data System 9T .45 ATLAS OF WC AND WO STARS 461 .65. TABLE 1 — Continued Typea Starb Other Name Instrument Comments 7ApJS. WC9 (cont.) WR 88 MR 70 SIT 198 WR 92 HD 157451 SIT WR 95 MR 74 SIT WR 96 LSS 4265 SIT No red observation WR 103 HD 164270 SIT Blue is nonphotometric WR 104 MR 80 SIT Air mass of red observation =1.59; blue and red observations have different fluxes WR 106 HDE 313653, MR 82 1RS, SIT 1RS air mass = 1.72; blue SIT is nonphotometric WR 119 LS 15 1RS Air mass of red observation =1.63 WR 121 MR 90 1RS X < 3556 A nonphotometric aFrom Torres, Conti, and Massey 1986. Stars that show absorption lines in their spectrum are indicated by a plus sign. bWR number from the Catalogue. BR number from the compilation of W-R stars in the LMC (Breysacher 1981). Sk 188 is in the SMC. 4. Flux distribution of WC stars. Dereddened observa- TABLE 2 tions provide a test for models of extended stellar atmo- Equivalent Widths (A) of the Strongest Lines Measured from the spheres. 1RS and SIT Observations WR 106 WR 114 II. OBSERVATIONS AND REDUCTION (Â) 1RS SIT 1RS SIT a) Northern Hemisphere Stars 4650-4686 130 131 1170 1016 5131 46 49 All WC stars in the northern hemisphere were observed at 5411 ... 31 36 Kitt Peak by P. M. between 1980 October and 1983 February 5471 ... 37 41 with the intensified Reticon scanner (1RS) on the white 5590 6.8 6.8 55 62 spectrograph at the No. 1 0.9 m telescope. The 1RS detector 5696 262 247 91 99 5801-5812 74 72 1166 11T package consists of an ITT proximity-focused image tube 5875 64 64 followed by a microchannel inverter image intensifier and a 6562 ... 142 162 dual Reticon array of 936 pixels with a fiber optic window. 6579 161 151 Only 820 pixels are usable because of distortion and vignet- 6735 ... 245 244 ting at the edge of the image-tube field.

Load more