Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2

Details Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2 Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2

2011-08-25

arxiv.org/abs/1108.5186v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Resubmitted to MNRAS after addressing referee's comments

Scientific paper

[Abridged] This work concerns very faint (R_lim=28 AB mag; M_(stars, lim) ~ 10^8 Msun), UV-selected sub-L* BX galaxies at z~2.3. Stellar masses, dust content, and dust-corrected SFRs are constrained using broadband SED fitting, giving insights into the nature of these low-mass systems. First, a correlation found between rest-frame UV luminosity and galaxy stellar mass suggests that many sub-L* galaxies at z~2.3 may have approximately constant star formation histories. A nearly-linear relation between stellar mass and star formation rate is also found, hinting that the rate at which a sub-L* BX galaxy forms its stars is directly related to the mass of stars that it has already formed. A possible explanation is that new gas that falls onto the galaxy's host halo along with accreting dark matter is the source of fuel for ongoing star formation. The instantaneous efficiency of star formation is low in this scenario, of order 1%. The low-mass end of the stellar mass function is steeper than expected from extrapolations of shallower surveys, resulting in a SMD at z~2.3 that's ~25% of the present-day value; this value is z~1.5-2x higher than that given by extrapolations of shallower surveys, suggesting that the build-up of stellar mass in the universe has proceeded more rapidly than previously thought. An update to the KDF z~2 UV LF finds a steeper faint-end slope than previously reported, though not as steep as that found by Reddy & Steidel (2009). Finally, sub-L* galaxies at z~2 carry very small amounts of dust compared to their more luminous cousins, so that while only ~20% of 1700A photons escape from a typical M* galaxy, more than half make it out of an M*+3 one. This paucity of dust highlights the fact that sub-L* galaxies are not simple scaled copies of their more luminous cousins. It also suggests that sub-L* are important contributors to keeping the Universe ionized at z~2.

Affiliated with

Also associated with

No associations

Rating

Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2 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 Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stars, Dust, and the Growth of UV-Selected Sub-L* Galaxies at Redshift z~2 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-501276