Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21530903g&link_type=abstract
American Astronomical Society, AAS Meeting #215, #309.03; Bulletin of the American Astronomical Society, Vol. 42, p.307
Astronomy and Astrophysics
Astronomy
Scientific paper
Massive starbursts drive the evolution of galaxies at high redshift, but they can only be studied in detail in the nearby Universe where they are much rarer. The dwarf irregular galaxy NGC 1569 has always been considered the closest example of a true starburst, with exceptionally high sustained star formation (SF) over the last Gyr. This recent SF has been extensively constrainted by HST studies that reached to near the presumed magnitude of the tip of the red giant branch (TRGB). These studies could not address the onset of the most ancient SF or the triggering mechanism of the current starburst. Here we present new deep HST ACS/WFC photometry of the resolved stars in NGC 1569 that goes some 4 mag deeper than any previous HST observations. These data allowed us to unequivocally detect and measure the TRGB for the first time and show that NGC 1569 is considerably farther away than previously believed. At ˜3 Mpc it is actually a member of the IC 342 group of galaxies, instead of being a starburst in isolation. In addition to the TRGB, our increased photometric depth also gives access to the fainter red clump and horizontal branch features in the I vs V-I color-magnitude diagram (CMD) of NGC 1569, allowing us to constrain for the first time even the most ancient SFH of this extreme starburst through the use of synthetic CMDs. The area sampled by our ACS/WFC observations is some 25 times larger than in previous HST studies, allowing us to characterize the spatial variations of the SFH, from the central star forming regions of NGC 1569 out into the older and more sparsely populated "halo". The results reveal the evolutionary status of this extreme starburst over cosmic time.
Aloisi Alessandra
Grocholski Aaron J.
Mack Jennifer
van der Marel Roeland P.
No associations
LandOfFree
New Deep HST/ACS Photometry of NGC 1569: Constraining the Evolution of the Strongest Starburst in the Nearby Universe does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with New Deep HST/ACS Photometry of NGC 1569: Constraining the Evolution of the Strongest Starburst in the Nearby Universe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New Deep HST/ACS Photometry of NGC 1569: Constraining the Evolution of the Strongest Starburst in the Nearby Universe will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-961303