The Opacity of Spiral Galaxy Disks. IV. Radial Extinction Profiles from Counts of Distant Galaxies Seen through Foreground Disks

Citations Over TimeTop 10% of 2005 papers

Abstract

Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, Gonzalez et al. (1998) and Holwerda et al. (2005a) developed the ``Synthetic Field Method'' (SFM), which analyses synthetic fields constructed by adding various deep exposures of unobstructed background fields to the candidate foreground galaxy field. However it is limited by low statistics of the surviving field galaxies, hence the need to combine a larger sample of fields. This paper presents the first results for a sample of 32 deep HST/WFPC2 archival fields of 29 spirals. The radial profiles of average dust extinction in spiral galaxies based on calibrated counts of distant field galaxies is presented here, both for individual galaxies as well as for composites from our sample. The effects of inclination, spiral arms and Hubble type on the radial extinction profile are discussed. The dust opacity of the disk apparently arises from two distinct components; an optically thicker (A_I = 0.5-4 mag) but radially dependent component associated with the spiral arms and a relatively constant optically thinner disk (A_I = 0.5 mag).

Related Papers

• → The kinematics and structure of the neutral hydrogen in the barred spiral galaxy NGC 3359(1982)12 cited
• → On the nature of the galaxy NGC 5666(2003)8 cited
• A Star Forming Disk in the Elliptical Galaxy NGC 5173(1990)
• → Star formation in disk galaxies and its relation with spiral structure in numerical simulations(2022)1 cited
• → The Barred Galaxy NGC 7741(1983)