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

Abstract

[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.

Resubmitted to MNRAS after addressing referee's comments

References in corpus (8)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The stellar mass assembly of galaxies from z=0 to z=4. Analysis of a sample selected in the rest-frame near-infrared with Spitzer
• The Stellar, Gas and Dynamical Masses of Star-Forming Galaxies at z~2
• Multi-Wavelength Constraints on the Cosmic Star Formation History from Spectroscopy: the Rest-Frame UV, H-alpha, and Infrared Luminosity Functions at Redshifts 1.9<z<3.4
• The Galaxy Mass Function up to z=4 in the GOODS-MUSIC sample: into the epoch of formation of massive galaxies
• Differential Evolution of the UV Luminosity Function of Lyman Break Galaxies from z~5 to 3
• The impact of Spitzer infrared data on stellar mass estimates - and a revised galaxy stellar mass function at 0 < z < 5
• Keck Deep Fields. III. Luminosity-dependent Evolution of the Ultraviolet Luminosity and Star Formation Rate Densities at z~4, 3, and 2

Cited by in corpus (44)

• UV-continuum slopes at z~4-7 from the HUDF09+ERS+CANDELS observations: Discovery of a well-defined UV-color magnitude relationship for z>=4 star-forming galaxies
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• The Star Formation Main Sequence in the Hubble Space Telescope Frontier Fields
• GOODS-Herschel:dust attenuation properties of UV selected high redshift galaxies
• The JWST Extragalactic Mock Catalog: Modeling galaxy populations from the UV through the near-IR over thirteen billion years of cosmic history
• How Do Star-Forming Galaxies at Z>3 Assemble Their Masses?
• The MOSDEF Survey: Dissecting the star-formation rate vs. stellar mass relation using H$\alpha$ and H$\beta$ emission lines at z ~ 2
• Ultra-faint Ultraviolet Galaxies at z~2 Behind the Lensing Cluster Abell 1689: the Luminosity Function, Dust Extinction and Star Formation Rate Density
• Properties of $z\sim 3-6$ Lyman Break Galaxies. II. Impact of nebular emission at high redshift
• SEDfit: Software for Spectral Energy Distribution Fitting of Photometric Data
• HerMES: dust attenuation and star formation activity in UV-selected samples from z~4 to z~1.5
• Bright and Faint Ends of Ly$\alpha$ Luminosity Functions at $\text{z}=2$ Determined by the Subaru Survey: Implications for AGN, Magnification Bias, and ISM HI Evolution
• The galaxy UV luminosity function at z ~ 2 - 4; new results on faint-end slope and the evolution of luminosity density
• The Evolution Of The Faint End Of The UV Luminosity Function During The Peak Epoch Of Star Formation (1<z<3)
• Which galaxies dominate the neutral gas content of the Universe?
• Dust properties of Lyman break galaxies at $z\sim 3$
• Spatially-unresolved SED fitting can underestimate galaxy masses: a solution to the missing mass problem
• Missing Stellar Mass in SED Fitting: Spatially Unresolved Photometry can Underestimate Galaxy Masses
• The Very Faint End of the UV Luminosity Function over Cosmic Time: Constraints from the Local Group Fossil Record
• The evolution of the star forming sequence in hierarchical galaxy formation models
• UV & U-band luminosity functions from CLAUDS and HSC-SSP -- I. Using four million galaxies to simultaneously constrain the very faint and bright regimes to $z\sim 3$
• UVUDF: UV Luminosity Functions at the cosmic high-noon
• The VIMOS Ultra Deep Survey: Ly$\alpha$ Emission and Stellar Populations of Star-Forming Galaxies at 2<z<2.5
• Stellar Populations of Lyman Break Galaxies at z=1-3 in the HST/WFC3 Early Release Science Observations
• The Impact of Strong Gravitational Lensing on Observed Lyman-Break Galaxy Numbers at 4<z<8 in the GOODS and the XDF Blank Fields
• Dust attenuation up to z~2 in the AKARI North Ecliptic Pole Deep Field
• Lyman continuum leaking galaxies - Search strategies and local candidates
• Lyman-Break Galaxies at $z\sim 3$ in the Subaru Deep Field: Luminosity Function, Clustering and [OIII] Emission
• S2COSMOS: Evolution of Gas Mass with Redshift Using Dust Emission
• Across the Green Valley with HST grisms: colour evolution, crossing time-scales and the growth of the red sequence at $z=1.0-1.8$
• The numbers of z~2 star-forming and passive galaxies in 2.5 square degrees of deep CFHT imaging
• The stellar mass function and star formation rate-stellar mass relation of galaxies at z ~ 4 - 7
• The UV to FIR spectral energy distribution of star-forming galaxies in the redshift desert
• Probing the Physical Properties of z=4.5 Lyman Alpha Emitters with Spitzer
• Probing the Star Formation Main Sequence down to $10^8$ M${}_{\odot }$ at $1.0<z<3.0$
• Lyman break and UV-selected galaxies at z ~ 1: II. PACS-100um/160um FIR detections
• Steadily Increasing Star Formation Rates in Galaxies Observed at 3 <~ z <~ 5 in the CANDELS/GOODS-S Field
• Abundant Serendipitous Emission Line Sources with JWST/NIRSpec
• Probing the Diffuse Lyman-alpha Emission on Cosmological Scales: Lyα Emission Intensity Mapping Using the Complete SDSS-IV eBOSS Survey
• Angular clustering of z~2 star-forming and passive galaxies in 2.5 square degrees of deep CFHT imaging
• LARgE Survey. I. Dead Monsters: the Massive End of the Passive Galaxy Stellar Mass Function at Cosmic Noon
• MUSUBI (MegaCam Ultra-deep Survey: $u^{\ast }$-Band Imaging)-Data for the COSMOS and SXDS Fields
• A Gravitational Lens Model for the Lya Emitter, LAE 221724+001716 at z=3.1 in the SSA 22 Field
• The impact of selection criteria on the properties of green valley galaxies