We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
The evolving slope of the stellar mass function at 0.6 ≤ z < 4.5 from deep WFC3 data.
- Authors
Santini, P.; Fontana, A.; Grazian, A.; Salimbeni, S.; Fontanot, F.; Paris, D.; Boutsia, K.; Castellano, M.; Fiore, F.; Gallozzi, S.; Giallongo, E.; Koekemoer, A. M.; Menci, N.; Pentericci, L.; Somerville, R. S.
- Abstract
We used Early Release Science (ERS) observations taken with the Wide Field Camera 3 (WFC3) in the GOODS-S field to study the galaxy stellar mass function (GSMF) at 0.6 ≤ z < 4.5. Deep WFC3 near-IR data (for Y as faint as 27.3, J and H as faint as 27.4 AB mag at 5σ), as well as deep KS (as faint as 25.5 at 5σ) Hawk-I band data, provide an exquisite data set with which determine in an unprecedented way the low-mass end of the GSMF, allowing an accurate probe of masses as low as M" ≃ 7.6 × 109 M☉ at z ∼ 3. Although the area used is relatively small (∼33 arcmin2), we found generally good agreement with previous studies on the entire mass range. Our results show that the slope of the faint-end increases with redshift, from α = -1.44± 0.03 at z ∼ 0.8 to α = -1.86± 0.16 at z ∼ 3, although indications exist that it does not steepen further between z ∼ 3 and z ∼ 4. This result is insensitive to any uncertainty in the M" parameter. The steepness of the GSMF faint-end solves the well-known disagreement between the stellar mass density (SMD) and the integrated star-formation history at z > 2. However, we confirm that there appears to be an excess of integrated star formation with respect to the SMD at z < 2, by a factor of ∼2-3. Our comparison of the observations with theoretical predictions shows that the models forecast a greater abundance of low mass galaxies, at least up to z ∼ 3, as well as a dearth of massive galaxies at z ∼ 4 with respect to the data, and that the predicted SMD is generally overestimated at z ≲ 2.
- Subjects
STAR formation; STELLAR evolution; STELLAR mass; REDSHIFT; ASTROPHYSICS
- Publication
Astronomy & Astrophysics / Astronomie et Astrophysique, 2012, Vol 538, p1
- ISSN
0004-6361
- Publication type
Article
- DOI
10.1051/0004-6361/201117513