We present the first results of the K-band Multi-Object Spectrometer (KMOS) Lens-Amplified Spectroscopic Survey, a new ESO Very Large Telescope large program, doing multi-object integral field ...spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the Hubble Space Telescope (HST) Grism Lens-Amplified Survey from Space. Using the power of the cluster magnification, we are able to reveal the kinematic structure of 25 galaxies at , in four cluster fields, with stellar masses . This sample includes five sources at with lower stellar masses than in any previous kinematic integral field unit (IFU) surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find that no galaxies with stellar mass in our sample display regular ordered rotation. Using the enhanced spatial resolution from lensing, we resolve a lower number of dispersion-dominated systems compared to field surveys, competitive with findings from surveys using adaptive optics. We find that the KMOS IFUs recover emission line flux from HST grism-selected objects more faithfully than slit spectrographs. With artificial slits, we estimate that slit spectrographs miss, on average, 60% of the total flux of emission lines, which decreases rapidly if the emission line is spatially offset from the continuum.
We present a gravitational-lensing model of MACS J1149.5+2223 using ultra-deep Hubble Frontier Fields imaging data and spectroscopic redshifts from HST grism and Very Large Telescope (VLT)/MUSE ...spectroscopic data. We create total mass maps using 38 multiple images (13 sources) and 608 weak-lensing galaxies, as well as 100 multiple images of 31 star-forming regions in the galaxy that hosts supernova Refsdal. We find good agreement with a range of recent models within the HST field of view. We present a map of the ratio of projected stellar mass to total mass (f ) and find that the stellar mass fraction for this cluster peaks on the primary BCG. Averaging within a radius of 0.3 Mpc, we obtain a value of , consistent with other recent results for this ratio in cluster environments, though with a large global error (up to δf = 0.005) primarily due to the choice of IMF. We compare values of f and measures of star formation efficiency for this cluster to other Hubble Frontier Fields clusters studied in the literature, finding that MACS1149 has a higher stellar mass fraction than these other clusters but a star formation efficiency typical of massive clusters.
Abstract
We present the results of ALMA spectroscopic follow-up of a
z
= 6.766 Ly
α
emitting galaxy behind the cluster RX J1347.1−1145. We report the detection of C
ii
158
μ
m line fully consistent ...with the Ly
α
redshift and with the peak of the optical emission. Given the magnification of
μ
= 5.0 ± 0.3, the intrinsic (corrected for lensing) luminosity of the C
ii
line is
L
C
ii
, roughly ∼5 times fainter than other detections of
z
∼ 7 galaxies. The result indicates that low
L
C
ii
in
z
∼ 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset (
) between the Ly
α
and C
ii
line is unusual, and may be indicative of ionizing photons escaping.
We present the results of ALMA spectroscopic follow-up of a z = 6.766 Ly alpha emitting galaxy behind the cluster RX J1347.1-1145. We report the detection of C II 158 mu m line fully consistent with ...the Ly alpha redshift and with the peak of the optical emission. Given the magnification of mu = 5.0 +/- 0.3, the intrinsic (corrected for lensing) luminosity of the C II line is LC II= 1.4(-0.3)(+0.3) x 10(7) L-circle dot, roughly similar to 5 times fainter than other detections of z similar to 7 galaxies. The result indicates that low LC II in z similar to 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset (Delta v = 20(-40)(+40) km s(-1)) between the Ly alpha and C II line is unusual, and may be indicative of ionizing photons escaping.
We present the results of ALMA spectroscopic follow-up of a z= 6.766 Lyalpha emitting galaxy behind the cluster RX J1347.1?1145. We report the detection of Cii 158 mu m line fully consistent with the ...Lyalpha redshift and with the peak of the optical emission. Given the magnification of mu= 5.0 + or - 0.3, the intrinsic (corrected for lensing) luminosity of the CII line is L sub(CII)= (ProQuest: Formulae and/or non-USASCII text omitted), roughlt ~5 times fainter than other detections of z~ 7 galaxies. The result indicates that low L sub(CII) in z~ 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset (Delta sub(nu)= (ProQuest: Formulae and/or non-USASCII text omitted)) between the Lyalpha and CII line is unusual, and may be indicative of ionizing photons escaping.
We present the results of ALMA spectroscopic follow-up of a z = 6.766 Ly emitting galaxy behind the cluster RX J1347.1−1145. We report the detection of C ii 158 m line fully consistent with the Ly ...redshift and with the peak of the optical emission. Given the magnification of = 5.0 0.3, the intrinsic (corrected for lensing) luminosity of the C ii line is LC ii , roughly ∼5 times fainter than other detections of z ∼ 7 galaxies. The result indicates that low LC ii in z ∼ 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset ( ) between the Ly and C ii line is unusual, and may be indicative of ionizing photons escaping.
We present a gravitational lensing model of MACS J1149.5+2223 using ultra-deep Hubble Frontier Fields imaging data and spectroscopic redshifts from HST grism and VLT/MUSE spectroscopic data. We ...create total mass maps using 38 multiple images (13 sources) and 608 weak lensing galaxies, as well as 100 multiple images of 31 star-forming regions in the galaxy that hosts Supernova Refsdal. We find good agreement with a range of recent models within the HST field of view. We present a map of the ratio of projected stellar mass to total mass (\(f_{\star}\)), and find that the stellar mass fraction for this cluster peaks on the primary BCG. Averaging within a radius of 0.3 Mpc, we obtain a value of \(\langle f_{\star} \rangle = 0.012^{+0.004}_{-0.003}\), consistent with other recent results for this ratio in cluster environments, though with a large global error (up to \(\delta f_{\star} = 0.005\)) primarily due to the choice of an IMF. We compare values of \(f_{\star}\) and measures of star formation efficiency for this cluster to other Hubble Frontier Fields clusters studied in the literature, finding that MACS1149 has a higher stellar mass fraction than these other clusters, but a star formation efficiency typical of massive clusters.
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