%0 Generic %1 alavi2013ultrafaint %A Alavi, Anahita %A Siana, Brian %A Richard, Johan %A Stark, Daniel P. %A Scarlata, Claudia %A Teplitz, Harry I. %A Freeman, William R. %A Dominguez, Alberto %A Rafelski, Marc %A Robertson, Brant %A Kewley, Lisa %D 2013 %K cluster function galaxy luminosity %T Ultra-faint Ultraviolet Galaxies at z~2 Behind the Lensing Cluster Abell 1689: the Luminosity Function, Dust Extinction and Star Formation Rate Density %U http://arxiv.org/abs/1305.2413 %X We have obtained deep HST ultraviolet (F275W/F336W) imaging of the lensing cluster Abell1689. The images are used to identify z~2 star-forming galaxies via their Lyman break. Because of the unprecedented depth of the images and the large magnification provided by the cluster, we detect galaxies 100x fainter than previous surveys at this redshift. After removing multiple images, we have 58 galaxies in our sample between -19.5 < MUV < -13. Because the mass distribution of Abell 1689 is well constrained, we are able to calculate the intrinsic sensitivity of the observations as a function of source plane position, allowing determinations of effective volume as a function of luminosity. We fit the faint-end slope of the luminosity function with our data alone to be alpha=-1.56 +/- 0.13, somewhat shallower than the values obtained at z > 3. There is no turnover in the luminosity function down to MUV = -13. The observed trend of increasingly redder UV spectral slopes with luminosity at higher redshifts is observed in our sample, but with redder slopes at all luminosities and average reddening of <E(B-V)>= 0.15. We assume the stars in these galaxies are metal poor (0.2 Z_sun) compared to their brighter counterparts (Z_sun), resulting in bluer assumed intrinsic UV slopes and larger derived dust extinction. The total UV luminosity density at z~2 is 4.3 x 10^26 erg/s/Hz/Mpc^3, 80% of which is emitted by galaxies in the luminosity range of our sample. Finally, we determine the star formation rate density from UV-selected galaxies at z~2 (assuming constant dust extinction correction of 4.2 over all luminosities and a Kroupa IMF) of 0.147 M_sun/yr/Mpc^3, significantly higher than previous determinations because of the additional fainter galaxies and the larger dust correction factors.abridged

@misc{alavi2013ultrafaint, abstract = {We have obtained deep HST ultraviolet (F275W/F336W) imaging of the lensing cluster Abell1689. The images are used to identify z~2 star-forming galaxies via their Lyman break. Because of the unprecedented depth of the images and the large magnification provided by the cluster, we detect galaxies 100x fainter than previous surveys at this redshift. After removing multiple images, we have 58 galaxies in our sample between -19.5 < MUV < -13. Because the mass distribution of Abell 1689 is well constrained, we are able to calculate the intrinsic sensitivity of the observations as a function of source plane position, allowing determinations of effective volume as a function of luminosity. We fit the faint-end slope of the luminosity function with our data alone to be alpha=-1.56 +/- 0.13, somewhat shallower than the values obtained at z > 3. There is no turnover in the luminosity function down to MUV = -13. The observed trend of increasingly redder UV spectral slopes with luminosity at higher redshifts is observed in our sample, but with redder slopes at all luminosities and average reddening of <E(B-V)>= 0.15. We assume the stars in these galaxies are metal poor (0.2 Z_{sun}) compared to their brighter counterparts (Z_{sun}), resulting in bluer assumed intrinsic UV slopes and larger derived dust extinction. The total UV luminosity density at z~2 is 4.3 x 10^26 erg/s/Hz/Mpc^3, 80% of which is emitted by galaxies in the luminosity range of our sample. Finally, we determine the star formation rate density from UV-selected galaxies at z~2 (assuming constant dust extinction correction of 4.2 over all luminosities and a Kroupa IMF) of 0.147 M_{sun}/yr/Mpc^3, significantly higher than previous determinations because of the additional fainter galaxies and the larger dust correction factors.[abridged]}, added-at = {2013-05-13T11:37:43.000+0200}, author = {Alavi, Anahita and Siana, Brian and Richard, Johan and Stark, Daniel P. and Scarlata, Claudia and Teplitz, Harry I. and Freeman, William R. and Dominguez, Alberto and Rafelski, Marc and Robertson, Brant and Kewley, Lisa}, biburl = {https://www.bibsonomy.org/bibtex/2d6233221bf10df89bebdddada420f225/miki}, description = {[1305.2413] Ultra-faint Ultraviolet Galaxies at z~2 Behind the Lensing Cluster Abell 1689: the Luminosity Function, Dust Extinction and Star Formation Rate Density}, interhash = {a966ffc35cfccfd2850d3442d5983cb0}, intrahash = {d6233221bf10df89bebdddada420f225}, keywords = {cluster function galaxy luminosity}, note = {cite arxiv:1305.2413Comment: 14 pages, 10 figures, 4 tables, submitted to ApJ}, timestamp = {2013-05-13T11:37:43.000+0200}, title = {Ultra-faint Ultraviolet Galaxies at z~2 Behind the Lensing Cluster Abell 1689: the Luminosity Function, Dust Extinction and Star Formation Rate Density}, url = {http://arxiv.org/abs/1305.2413}, year = 2013 }