Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-10-25
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
14 pages, 7 figures, 2 tables. MNRAS in press
Scientific paper
We present three dimensional spectroscopy of eleven E+A galaxies, selected for their strong H-delta absorption but weak (or non-existent) [OII]3727 and H-alpha emission. This selection suggests that a recent burst of star-formation was triggered but subsequently abruptly ended. We probe the spatial and spectral properties of both the young (~1Gyr) and old (few Gyr) stellar populations. Using the H-delta equivalent widths we estimate that the burst masses must have been at least 10% by mass (Mburst~10^10Mo), which is also consistent with the star-formation history inferred from the broad-band SEDs. On average the A-stars cover ~33% of the galaxy image, extending over 2-15kpc^2, indicating that the characteristic E+A signature is a property of the galaxy as a whole and not due to a heterogeneous mixture of populations. In approximately half of the sample, we find that the A-stars, nebular emission, and continuum emission are not co-located, suggesting that the newest stars are forming in a different place than those that formed ~1Gyr ago, and that recent star-formation has occurred in regions distinct from the oldest stellar populations. At least ten of the galaxies (91%) have dynamics that class them as "fast rotators" with magnitudes and dynamics comparable to local ellipticals and S0's. We also find a correlation between the spatial extent of the A-stars and dynamics such that the fastest rotators tend to have the most compact A-star populations, providing new constraints on models that aim to explain the transformation of later type galaxies into early types. Finally, we show that there are no obvious differences between the line extents and kinematics of E+A galaxies detected in the radio (AGN) compared to non-radio sources, suggesting that AGN feedback does not play a dramatic role in defining their properties, or that its effects are short.
Balogh Michael
Bower Richard
Lucey John
McGee Sean
Miller Chris
No associations
LandOfFree
From Star-Forming Spirals to Passive Spheroids: Integral Field Spectroscopy of E+A Galaxies 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 From Star-Forming Spirals to Passive Spheroids: Integral Field Spectroscopy of E+A Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and From Star-Forming Spirals to Passive Spheroids: Integral Field Spectroscopy of E+A Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-716708