Cycle:1817161514PhaseII ID 12209: A Strong Lensing Measurement of the Evolution of Mass Structure in Giant Elliptical GalaxiesPhaseII ID 12210: SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller RadiiPhaseII ID 12292: SWELLS: doubling the number of disk-dominated edge-on spiral lens galaxiesPhaseII ID 12209A Strong Lensing Measurement of the Evolution of Mass Structure in Giant Elliptical Galaxies45 TargetsPrincipal InvestigatorProf. Adam S. Bolton (University of Utah)Co-InvestigatorsDr. Joel R. Brownstein (University of Utah)Prof. Natalia Connolly (Hamilton College)Prof. Christopher S. Kochanek (The Ohio State University Research Foundation)Dr. Claudia Maraston (University of Portsmouth)Dr. Nicholas Ross (Lawrence Berkeley National Laboratory)Dr. David J. Schlegel (Lawrence Berkeley National Laboratory)Dr. Stella Seitz (Universitats-Sternwarte Munchen)Dr. David Wake (Yale University)Prof. Michael Wood-Vasey (University of Pittsburgh)AbstractThe structure and evolution of giant elliptical galaxies provide key quantitative tests for the theory of hierarchical galaxy formation in a cold dark matter dominated universe. Strong gravitational lensing provides the only direct means for the measurement of individual elliptical galaxy masses beyond the local universe, but there are currently no large and homogeneous samples of strong lens galaxies at significant cosmological look-back time. Hence, an accurate and unambiguous measurement of the evolution of the mass- density structure of elliptical galaxies has until now been impossible. Using spectroscopic data from the recently initiated Baryon Oscillation Spectroscopic Survey (BOSS) of luminous elliptical galaxies at redshifts from approximately 0.4 to 0.7, we have identified a large sample of high- probability strong gravitational lens candidates at significant cosmological look-back time, based on the detection of emission-line features from more distant galaxies along the same lines of sight as the target ellipticals. We propose to observe 45 of these systems with the ACS-WFC in order to confirm the incidence of lensing and to measure the masses of the lens galaxies. We will complement these lensing mass measurements with stellar velocity dispersions from ground-based follow-up spectroscopy. In combination with similar data from the Sloan Lens ACS (SLACS) Survey at lower redshifts, we will directly measure the cosmic evolution of the ratio between lensing mass and dynamical mass, to reveal the structural explanation for the observed size evolution of elliptical galaxies (at high mass). We will also measure the evolution of the logarithmic mass-density profile of massive ellipticals, which is sensitive to the details of the merging histories through which they are assembled. Finally, we will use our lensing mass-to-light measurements to translate the BOSS galaxy luminosity function into a mass function, and determine its evolution in combination with data from the original Sloan Digital Sky Survey.Observations Description45 visits.1 target per visit, 1 visit per target.One orbit of ACS-WFC F814W ACCUM per target.4 sub-exposures each target in ACS-WFC-DITHER-BOX pattern to pack orbit.Program TypeGOScientific CategoryUnresolved Stellar Populations and Galaxy StructureScientific KeywordsDark Matter, Elliptical Galaxies, Galaxy Formation And Evolution, Galaxy Morphology And Structure, Gravitational LensingStart Date2011-08-05 13:43:33StatusWaiting for initial orbit.PhaseII ID 12210SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller Radii137 TargetsPrincipal InvestigatorProf. Adam S. Bolton (University of Utah)Co-InvestigatorsDr. Joel R. Brownstein (University of Utah)Dr. Matthew Auger (University of Cambridge)Dr. Oliver Czoske (Kapteyn Astronomical Institute)Dr. Raphael Gavazzi (CNRS, Institut d'Astrophysique de Paris)Prof. Leon Koopmans (Kapteyn Astronomical Institute)Dr. Philip J. Marshall (University of California at Santa Barbara)Dr. Leonidas Moustakas (Jet Propulsion Laboratory)Prof. Tommaso Treu (University of California at Santa Barbara)AbstractStrong gravitational of mass in the central regions of early-type galaxies (ETGs). We propose to continue the highly productive Sloan Lens ACS (SLACS) Survey for strong gravitational lens galaxies by observing a substantial fraction of 135 new ETG gravitational-lens candidates with HST-ACS WFC F814W Snapshot imaging. The proposed target sample has been selected from the seventh and final data release of the Sloan Digital Sky Survey, and is designed to complement the distribution of previously confirmed SLACS lenses in lens-galaxy mass and in the ratio of Einstein radius to optical half-light radius. The observations we propose will lead to a combined SLACS sample covering nearly two decades in mass, with dense mapping of enclosed mass as a function of radius out to the half-light radius and beyond. With this longer mass baseline, we will extend our lensing and dynamical analysis of the mass structure and scaling relations of ETGs to galaxies of significantly lower mass, and directly test for a transition in structural and dark-matter content trends at intermediate galaxy mass. The broader mass coverage will also enable us to make a direct connection to the structure of well-studied nearby ETGs as deduced from dynamical modeling of their line-of-sight velocity distribution fields. Finally, the combined sample will allow a more conclusive test of the current SLACS result that the intrinsic scatter in ETG mass-density structure is not significantly correlated with any other galaxy observables. The final SLACS sample at the conclusion of this program will comprise approximately 130 lenses with known foreground and background redshifts, and is likely to be the largest confirmed sample of strong-lens galaxies for many years to come.Observations DescriptionAll targets 1 x 420s ACS-WFC F814W.There should be one exposure per visit, one visit per target, and identical specifications for all. Targets are to be centered in the WFC1 aperture. No CR split, because we want to keep read noise down (we are read-noise limited at these short exposure times). These exposures do not pack the orbit, but rather minimize the visit time within acceptable limits so as to achieve the best possible snapshot execution likelihood.Program TypeSNAPSScientific CategoryUnresolved Stellar Populations and Galaxy StructureScientific KeywordsDark Matter, Elliptical Galaxies, Galaxy Formation And Evolution, Galaxy Morphology And Structure, Gravitational LensingStart Date2012-04-11 17:20:35StatusWaiting for initial orbit.PhaseII ID 12292SWELLS: doubling the number of disk-dominated edge-on spiral lens galaxies22 TargetsPrincipal InvestigatorProf. Tommaso Treu (University of California at Santa Barbara)Co-InvestigatorsDr. Brendon J. Brewer (University of California at Santa Barbara)Dr. Aaron Dutton (University of Victoria)Dr. Matthew Auger (University of Cambridge)Prof. Leon Koopmans (Kapteyn Astronomical Institute)Prof. Adam S. Bolton (University of Utah)Dr. Leonidas Moustakas (Jet Propulsion Laboratory)Dr. Oliver Czoske (Kapteyn Astronomical Institute)Dr. Raphael Gavazzi (CNRS, Institut d'Astrophysique de Paris)Dr. Philip J. Marshall (University of California at Santa Barbara)AbstractThe formation of realistic disk galaxies within the LCDM cosmology is still largely an unsolved problem. Theory is now beginning to make predictions for how dark matter halos respond to galaxy formation, and for the properties of disk galaxies. Measuring the density profiles of dark matter halos on galaxy scales is therefore a strong test for the standard paradigm of galaxy formation, offering great potential for discovery. However, the degeneracy between the stellar and dark matter contributions to galaxy rotation curves remains a major obstacle. Strong gravitational lensing, when combined with spatially resolved kinematics and stellar population models, can solve this long-standing problem. Unfortunately, this joint methodology could not be exploited until recently due to the paucity of known edge-on spiral lenses. We have developed and demonstrated an efficient technique to find exactly these systems. During supplemental cycle-16 we discovered five new spiral lens galaxies, suitable for rotation curve measurements. We propose multi-color HST imaging of 16 candidates and 2 partially-imaged confirmed systems, to measure a sample of eight new edge-on spiral lenses. This program will at least double the number of known disk-dominated systems. This is crucial for constraining the relative contribution of the disk, bulge and dark halo to the total density profile.Observations DescriptionThe goal of our observations is to obtain high signal-to-noise spatially-resolved photometry through three filters, spanning the largest possible wavelength range to correct for dust extinction, identify multiple images by their equal colors, and determine the relative stellar mass-to-light ratio of the bulge and disk components. Precise removal of the lens galaxy contamination, including its differential extinction, is key to the success of the study of spiral lens galaxies. The following strategy with ACS/WFC3 will allow us to meet our goals:In the optical we choose ACS with filters F435W-F814W because this is the fastest setup (thus maximizing the S/N in the images) covering a long wavelength baseline. For those 4 systems that cannot be observed from the ground with laser guide star adaptive optics in the infrared, we will also observe them with the IR channel of WFC3 through F160W, which is the reddest broad filter with low background.Based on our previous experience with WFPC2 and ACS, one ACS orbit split between F435W and F814W bands is sufficient to achieve S/N~5 per pixel at the location of the Einstein Ring, sufficient for good lensing modeling; this includes the extra noise caused by removal of foreground structure and differential extinction. The signal-to-noise ratio is also sufficient to determine structural parameters of bulges and disks to a level that is dominated by systematic errors, rather than photon-counting. The ACS observations will be split into two exposures using a 2-point dither pattern, to improve sampling of the PSF and ensure cosmic ray/bad pixel removal. In the infrared, based on our experience with the WFC3-IR images obtained as part of the SLACS survey, we will require a full orbit to reach an equivalent S/N per pixel as in the optical bands and perform accurate dust corrections. The IR observations will be split into four exposures using a 4-point dither pattern. This strategy will allow us to recover most of the resolution lost to the relatively poor sampling of the IR PSF.Program TypeGOScientific CategoryCosmologyScientific KeywordsDark Matter, Dynamics, Galaxy Disks, Galaxy Formation And Evolution, Galaxy Morphology And StructureStart Date2010-09-06 14:39:54StatusWaiting for initial orbit.
University of UtahProf. Adam S. BoltonCycle 18 12209 Principal Investigator, Cycle 18 12210 Principal Investigator, Cycle 15 10886 Principal Investigator, Cycle 14 10174 Principal Investigator, Cycle 14 10587 Principal Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11701 Co-Investigator, Cycle 17 11978 Co-Investigator, Cycle 16 11202 Co-Investigator, Cycle 15 10798 Co-Investigator, Cycle 15 10831 Co-Investigator, Cycle 14 10494 Co-InvestigatorDr. Joel R. BrownsteinCycle 18 12209 Co-Investigator, Cycle 18 12210 Co-Investigator, Cycle 14 10174 Co-InvestigatorMr. Yiping ShuCycle 18 12209 STSCI Investigator, Cycle 18 12210 STSCI Investigator, Cycle 17 11701 STSCI Investigator, Cycle 17 11978 STSCI Investigator, Cycle 16 11202 STSCI Investigator, Cycle 15 10798 STSCI Investigator, Cycle 15 10831 STSCI Investigator, Cycle 15 10886 STSCI Investigator, Cycle 14 10174 STSCI Investigator, Cycle 14 10494 STSCI Investigator, Cycle 14 10587 STSCI Investigator University of California at Santa BarbaraProf. Tommaso TreuCycle 18 12292 Principal Investigator, Cycle 17 11701 Principal Investigator, Cycle 17 11978 Principal Investigator, Cycle 18 12210 Co-Investigator, Cycle 16 11202 Co-Investigator, Cycle 15 10798 Co-Investigator, Cycle 15 10886 Co-Investigator, Cycle 14 10174 Co-Investigator, Cycle 14 10494 Co-Investigator, Cycle 14 10587 Co-InvestigatorDr. Philip J. MarshallCycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11701 Co-Investigator, Cycle 17 11978 Co-InvestigatorDr. Brendon J. BrewerCycle 18 12292 Co-Investigator Kapteyn Astronomical InstituteDr. Oliver CzoskeCycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11978 Co-Investigator, Cycle 16 11202 Co-InvestigatorProf. Leon KoopmansCycle 16 11202 Principal Investigator, Cycle 15 10798 Principal Investigator, Cycle 14 10174 Principal Investigator, Cycle 14 10494 Principal Investigator, Cycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11701 Co-Investigator, Cycle 17 11978 Co-Investigator, Cycle 15 10886 Co-Investigator, Cycle 14 10587 Co-InvestigatorDr. M. BarnabeCycle 15 10798 Co-Investigator Lawrence Berkeley National LaboratoryDr. Nicholas RossCycle 18 12209 Co-InvestigatorDr. David J. SchlegelCycle 18 12209 Co-Investigator Yale UniversityDr. David WakeCycle 18 12209 Co-Investigator Jet Propulsion LaboratoryDr. Leonidas MoustakasCycle 15 10831 Principal Investigator, Cycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11701 Co-Investigator, Cycle 17 11978 Co-Investigator, Cycle 16 11202 Co-Investigator, Cycle 15 10798 Co-Investigator, Cycle 15 10886 Co-Investigator, Cycle 14 10174 Co-Investigator, Cycle 14 10494 Co-Investigator, Cycle 14 10587 Co-Investigator The Ohio State University Research FoundationProf. Christopher S. KochanekCycle 18 12209 Co-Investigator University of PittsburghProf. Michael Wood-VaseyCycle 18 12209 Co-Investigator Hamilton CollegeProf. Natalia ConnollyCycle 18 12209 Co-Investigator University of PortsmouthDr. Claudia MarastonCycle 18 12209 Co-Investigator CNRS, Institut d'Astrophysique de ParisDr. Raphael GavazziCycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11701 Co-Investigator, Cycle 17 11978 Co-Investigator, Cycle 16 11202 Co-Investigator Universitats-Sternwarte MunchenDr. Stella SeitzCycle 18 12209 Co-Investigator University of VictoriaDr. Aaron DuttonCycle 18 12292 Co-Investigator, Cycle 17 11978 Co-Investigator Massachusetts Institute of TechnologyProf. Scott BurlesCycle 16 11202 Co-Investigator, Cycle 15 10798 Co-Investigator, Cycle 15 10831 Co-Investigator, Cycle 15 10886 Co-Investigator, Cycle 14 10174 Co-Investigator, Cycle 14 10494 Co-Investigator, Cycle 14 10587 Co-Investigator Space Telescope Science InstituteDr. Karen LevayCycle 17 11701 STSCI Investigator, Cycle 17 11978 STSCI Investigator, Cycle 16 11202 STSCI Investigator, Cycle 15 10798 STSCI Investigator, Cycle 15 10831 STSCI Investigator, Cycle 15 10886 STSCI Investigator, Cycle 14 10174 STSCI Investigator, Cycle 14 10494 STSCI Investigator, Cycle 14 10587 STSCI InvestigatorDr. Brian McLeanCycle 17 11701 STSCI Investigator, Cycle 17 11978 STSCI Investigator, Cycle 16 11202 STSCI Investigator, Cycle 15 10798 STSCI Investigator, Cycle 15 10831 STSCI Investigator, Cycle 15 10886 STSCI Investigator, Cycle 14 10174 STSCI Investigator, Cycle 14 10494 STSCI Investigator, Cycle 14 10587 STSCI Investigator University of CambridgeDr. Matthew AugerCycle 18 12210 Co-Investigator, Cycle 18 12292 Co-Investigator, Cycle 17 11978 Co-Investigator
SDSSJ1430
Prof. Adam Bolton and postdoc Dr. Joel Brownstein are exploiting the unique wide-field spectroscopic capability of the Apache Point Observatory's 2.5-meter telescope, currently using the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS3) to discover new strong gravitational galaxy lenses.
In conjunction with follow-up Hubble Space Telescope (HST) single or multi-color images of the galaxy lenses detected in the Sloan Lens ACS (SLACS) survey, we are providing constraints on structure formation and galaxy evolution problems.