INVESTIGADORES
PIATTI Andres Eduardo
artículos
Título:
Background galaxies as reddening probes throughout the Magellanic Clouds
Autor/es:
DUTRA, C; BICA, EDUARDO; CLARIA OLMEDO, JUAN JOSÉ; PIATTI, ANDRÉS E.; AHUMADA, A.V.
Revista:
ASTRONOMY AND ASTROPHYSICS
Referencias:
Año: 2001 vol. 371 p. 895 - 907
ISSN:
0004-6361
Resumen:
We study the spectral properties in the range 3600 Å-6800 Å
of the nuclear region of galaxies behind the Magellanic Clouds. The
radial velocities clarified the nature of the objects as background
galaxies or extended objects belonging to the Clouds. For most galaxies
behind the main bodies of the LMC and SMC, radial velocities were
measured for the first time. In the present sample typical LMC
background galaxies are nearby (4000 < V(km s-1) <
6000), while SMC's are considerably more distant (10 000 < V(km
s-1) < 20 000). We determine the reddening in each line of
sight by matching a reddening-free galaxy template with comparable
stellar population. For the LMC main body we derive a combined Milky Way
and internal reddening value E(B-V)MW+i = 0.12 +/- 0.10,
while for the SMC E(B-V)MW+i = 0.05 +/- 0.05. By subtracting
Milky Way reddening values for galaxies projected onto the surroundings
of each Cloud, we estimate average internal reddening values Delta
E(B-V)i = 0.06 and 0.04, respectively for the main bodies of
the LMC and SMC. The Clouds are optically thin, at least in the
directions of the studied background galaxies which are often difficult
to be identified as such on ESO/SERC sky survey images. Nevertheless,
more reddened zones may occur where it is difficult to identify
galaxies.