Astronomy Letters, Vol. 30, No. 11, 2004, pp. 729–736. Translated from Pis’ma v Astronomicheski˘ı Zhurnal, Vol. 30, No. 11, 2004, pp. 803–811. Original Russian Text Copyright c 2004 by Tsvetkov, Pavlyuk, Bartunov. TheSAICatalogofSupernovaeandRadialDistributions of Supernovae of Various Types in Galaxies D. Yu. Tsvetkov*, N.N.Pavlyuk**,andO.S.Bartunov*** Sternberg Astronomical Institute, Universitetski ˘ı pr. 13, Moscow, 119992 Russia Received May 18, 2004 Abstract—We describe the Sternberg Astronomical Institute (SAI)catalog of supernovae. We show that the radial distributions of type-Ia, type-Ibc, and type-II supernovae differ in the central parts of spiral galaxies and are similar in their outer regions, while the radial distribution of type-Ia supernovae in elliptical galaxies differs from that in spiral and lenticular galaxies. We give a list of the supernovae that are farthest from the galactic centers, estimate their relative explosion rate, and discuss their possible origins. c 2004MAIK “Nauka/Interperiodica”. Key words: astronomical catalogs, supernovae, observations, radial distributions of supernovae. INTRODUCTION be found on the Internet. The most complete data are contained in the list of SNe maintained by the Cen- In recent years, interest in studying supernovae (SNe)has increased signi ficantly. Among other rea- tral Bureau of Astronomical Telegrams (http://cfa- sons, this is because SNe Ia are used as “standard www.harvard.edu/cfa/ps/lists/Supernovae.html)and candles” for constructing distance scales and for cos- the electronic version of the Asiago catalog mological studies, and because SNe Ibc may be re- (http://web.pd.astro.it/supern). lated to gamma ray bursts. Many new programs of searching for SNe using Studies of the SN distribution in galaxies are of modern CCD detectors and automated telescopes great interest in elucidating the nature of the stel- have been initiated, and the number of discoveries lar populations that provide SN explosions of a cer- per year has increased from 20–30 in the 1980s to tain type. Although the presupernova stars are cur- about 300 in the last several years. rently known for several SNe II (SN 1987A, 1993J, Therefore, the collection and systematization of 2003gd), the origin of presupernovae of other types is SN data and their presentation in a form convenient still an open question in many respects. Of particular for statistical and other studies are of particular inter- interest is the possible difference between the popula- est. tions of type-Ia presupernovae in galaxies of different The first lists of SNe appeared in the late 1950s types, which can affect the results of cosmological and were repeatedly updated as the number of dis- studies using them. covered objects increased (Zwicky 1958, 1965; Kowal and Sargent 1971; Sargent et al. 1974). The catalogs Despite the rapid increase in the amount of data, by Karpowicz and Rudnicki (1968)and Flin et the SN distributions in galaxies have been studied al. (1979)also contained a complete bibliography for rarely in recent years. After the paper of Bartunov each object. In the last twenty years, the Asiago Ob- et al. (1992), which gives references to previous pa- servatory catalog of supernovae (Barbon et al. 1984, pers, we note the works of van den Bergh (1997), 1989, 1999)has received the greatest recognition; Bartunov and Tsvetkov (1997), Wang et al. (1997), in addition to SN data, it also contains basic infor- mation about the host galaxies. A list of SNe was and Howell et al. (2000). Tsvetkov et al. (2001)com- included in the fifth volume of the General Catalog of pared the radial distributions of gamma ray bursts and Variable Stars (Artyukhina et al. 1995). At present, SNe Ibc. continuously updated lists and catalogs of SNe can Since the number of SNe discovered since the last *E-mail: [email protected] comprehensive studies of the radial distribution has **E-mail: [email protected] increased by more than a factor of 2, a new study ***E-mail: [email protected] would be of great interest. 1063-7737/04/3011-0729$26.00 c 2004 MAIK “Nauka/Interperiodica” 730 TSVETKOV et al. THE SAI CATALOG OF SUPERNOVAE The SNe are arranged in order of their increasing Description of the Catalog numbers assigned by the Central Bureau of Astro- nomical Telegrams of the International Astronomical For statistical studies of SNe, it is necessary to Union. collect data on all the discovered SNe and on their Initially, IAU Circulars served as the main sources host galaxies. of SN data. However, if these data are refined or mod- The SAI catalog of supernovae was originally in- ified in subsequent works, then appropriate changes tended precisely for statistical studies; its compilation are made to the catalog. was begun in 1986 on the basis of existing SN lists The identification of SN host galaxies, which is and published data. One version of the catalog was easy for bright and nearby objects, becomes increas- described by Tsvetkov and Bartunov (1993). ingly difficult, because the number of discovered faint The current version of the SAI catalog of super- and distant SNe has increased significantly in recent novae contains data on 2780 extragalactic SNe dis- years. In addition, difficulties arise when a SN ex- covered from 1885 until January 6, 2004, and on their plodes in a multiple system of galaxies or in a peculiar host galaxies. The catalog is accessible on the Inter- galaxy. Therefore, when compiling the catalog, the net: http://www.sai.msu.su/sn/sncat; it is also pos- sky field around each SN was studied using DSS sible to directly retrieve data from the catalog using a (http://archive.stsci.edu/dss/index.html). To find the number of key parameters (http://www.sai.msu.su/ most likely host galaxy, in addition to the sky posi- cgi-bin/wdb-p95/sn/sncat/form). tions, we also use data on the radial velocities and The catalog presents the following data: brightnesses of the galaxy and the SN. If the host (1)SN name; galaxy is multiple, this is specified in the description of the galaxy type. (2)Galaxy name; The main source of data on the host galaxies (3)Equatorial coordinates of the galaxy for epoch 2000.0; was the LEDA database (http://www-obs.univ- (4)Galaxy magnitude and its source; lyon1.fr/hypercat). However, the radial velocities (or redshifts)of the galaxies were taken from the (5)Position angle of the major axis of the galaxy; NED database (http://nedwww.ipac.caltech.edu). (6)Inclination of the galaxy to the plane of the sky; The magnitudes were taken from the UGC (Nil- (7)Radial velocity or redshift of the galaxy; son 1973)and ESO (Lauberts 1982)catalogs for (8)Morphological type of the galaxy from the RC3 most of the galaxies and from the LEDA database catalog (de Vaucouleurs et al. 1991); galaxy mem- and the PGC catalog (Paturel et al. 1989)and, if no bership in a double or triple system is additionally data were available in these sources, from the NED specified; database or IAU Circulars for fainter galaxies. (9)Logarithm of the apparent axial ratio of the In several cases, we compared our data and those galaxy; from the Asiago catalog and the SN list of the Cen- (10)Logarithm of the apparent length of the major tral Bureau of Astronomical Telegrams. However, the axis; catalogs are compiled independently. (11)Numerical code of the morphological type; (12)Galaxy luminosity class; Statistical Data (13)Galactocentric distance of the SN in the north–south and east–west directions, in arcsecs; Figure 1 shows the distribution of SN discoveries (14)SN magnitude; it is additionally speci fied in years, with the SNe discovered photographically whether this is the magnitude at maximum bright- being highlighted. We see a sharp increase in the ness determined from the light curve or an estimate number of discoveries in the mid-1990s and another at a certain time, most often at the discovery (the jump in 2001. The photographic searches for SNs magnitude at maximum could then be brighter); the ceased in 2000, but the number and fraction of SNe photometric band (if it is a standard one)is also given; discovered photographically began to decrease af- ter 1992. (15)Date of maximum SN brightness; The distributions in SN and galaxy types are (16)SN discovery date; shown in Figs. 2 and 3, respectively. These data are (17)SN type; similar to those of Barbon et al. (1999). (18)SN equatorial coordinates for epoch 2000.0; The SN redshift distribution is shown in Fig. 4. (19)Search program or observatory that discov- The programs of searching for distant SNe initiated ered the SN; in the mid-1990s have discovered mostly SNe Ia with (20)Discoverers’ names. 0.3 <z<1.0, while the “ordinary” programs have ASTRONOMY LETTERS Vol. 30 No. 11 2004 THE SAI CATALOG OF SUPERNOVAE 731 300 200 N 100 0 1900 1920 1940 1960 1980 2000 Years Fig. 1. Distribution of SN discoveries in years. The dark shading highlights the SNe discovered photographically. discovered SNe with z<0.1, with their distribution ously (Bartunov et al. 1992). For each SN, we calcu- peaking near z =0.02. lated the following quantities: the relative radial dis- The distribution of SNe in the plot of magnitude tance√ r and the radial distance√ in kiloparsecs R: r = against the logarithm of the product of the speed of 2 2 2 2 2 ∆α +∆δ /D25; R = Vr ∆α +∆δ /206.3H0, light by the redshift is shown in Fig. 5. The magni- where ∆α and ∆δ are the distances from the SN tudes for most of the SNe are the estimates at the to the Galactic center, D25 is the diameter of the time of their discovery and could be much larger than galaxy up to the 25m/ isophote, V is the radial those at maximum brightness.