Bibcode
Fernández-Ontiveros, J. A.; López-Sanjuan, C.; Montes, M.; Prieto, M. A.; Acosta-Pulido, J. A.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society: Letters, Volume 411, Issue 1, pp. L21-L25.
Advertised on:
2
2011
Citations
19
Refereed citations
18
Description
High spatial resolution near-infrared (NIR) images of the central 24
× 24 arcsec2 (˜2 × 2 kpc2) of
the elliptical galaxy NGC 1052 reveal a total of 25 compact sources
randomly distributed in the region. 15 of them exhibit Hα
luminosities an order of magnitude above the estimate for an evolved
population of extreme horizontal branch stars. Their Hα equivalent
widths and optical-to-NIR spectral energy distributions are consistent
with them being young stellar clusters aged <7 Myr. We consider this
to be the first direct observation of spatially resolved star-forming
regions in the central kiloparsecs of an elliptical galaxy. The sizes of
these regions are ≲11 pc and their median reddening is E(B-V)
˜ 1 mag. According to previous works, NGC 1052 may have
experienced a merger event about 1 Gyr ago. On the assumption that these
clusters are spread with a similar density over the whole galaxy, the
fraction of galaxy mass (5 × 10-5) and rate of star
formation (0.01 M&sun; yr-1) involved suggest the
merger event as the possible cause for the star formation we see today.
Based on European Southern Observatory (ESO) Very Large Telescope (VLT)
program 076.B-0493 and Hubble Space Telescope (HST) program IDs 3639,
6286, 7403 and 7886.