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INFORMATION to USERS the Most Advanced Technology Has Been An infrared and optical study of bright IRAS point sources of minimum apparent temperature Item Type text; Thesis-Reproduction (electronic) Authors Paley, Elizabeth Sara, 1967- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 29/09/2021 03:49:45 Link to Item http://hdl.handle.net/10150/277118 INFORMATION TO USERS The most advanced technology has been used to photo­ graph and reproduce this manuscript from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are re­ produced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. These are also available as one exposure on a standard 35mm slide or as a 17" x 23" black and white photographic print for an additional charge. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. University Microfilms International A Bell & Howell Information Company 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 313/761-4700 800/521-0600 Order Number 1338081 An infrared and optical study of bright IRAS point sources of minimum apparent temperature Paley, Elizabeth Sara, M.S. The University of Arizona, 1989 UMI 300 N. Zeeb Rd. Ann Arbor, MI 48106 AN INFRARED AND OPTICAL STUDY OF BRIGHT IRAS POINT SOURCES OF MINIMUM APPARENT TEMPERATURE by Elizabeth Sara Palty A Thesis Submitted to the Faculty of the DEPARTMENT OF ASTRONOMY In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 19 8 9 2 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgement of source is made. Requests for permis­ sion for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgement the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: APPROVAL OF THESIS DIRECTOR This thesis has been approved on the date shown below: Frank J. Low Date Professor of Astronomy 3 ACKNOWLEDGEMENT The author wishes to acknowledge the support and assistance of several peo­ ple without whom the work laid out in this thesis would not have been completed. First, thanks go to Roseanne Hernandez and others at IPAC who made ADDSCAN data available on extremely short notice. Thanks to Steve Larson for his time and interest in obtaining optical cirrus data using his CCD camera. Many thanks go to Roc Cutri, for 90" observing and for translating much of the Explanatory Supple­ ment. I thank John Black, Mark Sykes, Rex Saffer, Doug Kelly, Jim Bollinger, and especially Hans-Walter Rix for useful discussions, and Irene Barg and Mike Cobb for assistance with uairas. Sincere thanks to John McGraw for access to CTI, and to Tom Hess for pro­ grams and answers. Deepest gratitude to my advisor, Frank Low, for seeing this project through to the end, and especially for his support after I decided to change careers. Finally, thanks to Robert Schumann, without whom I would not have survived this summer. The Infrared Astronomical Satellite was developed and operated by the Nether­ lands Agency for Aerospace Programs (NIVR), the US National Aeronautics and Space Administration (NASA), and the UK Science and Enginerring Research Council (SERC). Use of the POSS and ESO photographic plates was made possible by Kitt Peak National Observatory. 4 TABLE OF CONTENTS ABSTRACT 5 I. INTRODUCTION 6 II. AN INFRARED AND OPTICAL SURVEY OF 100/xm SOURCES .... 7 a. Selection Criteria 7 b. Optical and Infrared Identification of Sources 8 c. Infrared Fluxes from ADDSCAN Data 11 d. Spatial Distribution of Cirrus 13 e. Discussion 14 III. OPTICAL COLORS OF CIRRUS USING CTI 15 IV. CONCLUSIONS 19 APPENDIX A: TABLES 21 APPENDIX B: FIGURES 31 REFERENCES 53 5 ABSTRACT A sample of 170 sources from the IRAS Point Source Catalog (PSC) having |6| > 40°, 100fj,m flux F4 > 2.5 Jy, and upper limit fluxes at 12, 25 and 60//m was studied on POSS and ESO photographic plates. 151 of these sources are identified as 'infrared cirrus,' thirteen as galaxies, and one as a planetary nebula; four sources lie in the Small Magellanic Cloud (SMC), and the remaining source is Saturn. Accurate infrared fluxes were obtained for 29 cirrus sources, the galaxies, and the planetary nebula. The colors of the cirrus sources support the hypothesis that the radiation is coming from a mixture of large, cool grains and Polycyclic Aromatic Hydrocarbons (PAHs), with large variation in relative abundances. Optical colors and surface brightness were obtained for one cirrus cloud using data from the CCD Transit Instrument on Kitt Peak. 6 I. INTRODUCTION In November 1983, the Infrared Astronomical Satellite (IRAS) completed an unbiased survey of 96% of the sky at wavelengths centered on 12, 25, 60 and lOO^m (bands 1, 2, 3 and 4, respectively). The 100/mi emission is characterized by extended, wispy clouds of 'infrared cirrus,' so named for its similarity in appearance to the terrestrial clouds (Low et al., 1984). IRAS skyflux images show detail in the cirrus down to arcminute resolution, while arms and rings of cirrus are seen to extend over tens of degrees. Earlier optical data had suggested the presence of such nebulosities (Sandage, 1976), and the IRAS 100/^m data correlated closely with optical emission in many regions (including Sandage, 1976; see also de Vries, 1985 and de Vries, 1986). One result of IRAS data processing is the Point Source Catalog (PSC). Sources in the PSC that are point sources '100/um only' (i.e. that are either undetected or resolved in the other three bands) should be the coldest objects seen by IRAS. For a variety of reasons, many regions of infrared cirrus made their way into the PSC as lOO^m only sources. Data at 100 and 12//m indicated that cirrus may be composed of both cold (~ 20 - 30 K) and hot (~ 100 - 1000 K) material, a mixture of graphite and silicate dust, and Polycyclic Aromatic Hydrocarbons (PAHs: Puget et al., 1985; de Vries, 1986). However, no systematic study had yet been done to see if all cirrus shows a large 12/j,m flux relative to 100/zm. At the outset of this research, we expected most 100/im point sources to be compact, isolated regions of cirrus. 7 Such sources would be ideal for study since they would be distinguishable from the surrounding medium. In addition, we expected the brightest, most compact infrared sources to have the brightest optical counterparts. We therefore selected a sample of the brightest 100/zm sources in the PSC for a systematic study of the infrared and optical properties of cirrus. We began our study using optical images to identify the sources in our sample. In the process, we learned that while most of the sources were cirrus, a significant fraction (11%) were not. This raised the additional question of whether these non- cirrus objects (galaxies and a planetary nebula) are extremely cold or managed to get into the PSC as 100/mi only sources due to a processing anomaly. Inspection of photographic plates and IRAS skyflux images gave us a quali­ tative view of the optical and infrared morphology and surface brightness of the 100/mi sources. We then used ADDSCANS, the one-dimensional IRAS coadded data, to obtain true infrared fluxes and size information for 43 sources. Lastly, we measured the optical colors of one cirrus cloud using data from the CCD Transit Instrument. II. AN INFRARED AND OPTICAL SURVEY OF lOO^m SOURCES a. Selection Criteria Our sample of sources was obtained by searching the IRAS PSC for all sources having high quality detections at 100/xm and only upper limit fluxes at 12, 25 and 60/zm (see Explanatory Supplement, 1984). Because we were interested in isolated 8 cirrus clouds, we limited our sample to sources having Galactic latitude |6| > 40°. There are 2512 such sources in the PSC. Because we were interested in the brightest sources, we chose a 100/mi flux limit of F4 > 2.5 Jy.
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