TDCOSMO. XI. New lensing galaxy redshift and velocity dispersion measurements from Keck spectroscopy of eight lensed quasar systems

Abstract

We have measured the redshifts and single-aperture velocity dispersions of eight lens galaxies using the data collected by the Echellette Spectrograph and Imager (ESI) and Low Resolution Imaging Spectrometer (LRIS) at W.M. Keck observatory on different observing nights spread over three years (2018-2020). These results, combined with other ancillary data, such as high-resolution images of the lens systems, and time delays, are necessary to increase the sample size of the quasar-galaxy lens systems for which the Hubble constant can be measured, using the time-delay strong lensing method, hence increasing the precision of its inference. Typically, the 2D spectra of the quasar-galaxy lens systems get spatially blended due to seeing by ground-based observations. As a result, the extracted lensing galaxy (deflector) spectra become significantly contaminated by quasar light, which affects the ability to extract meaningful information about the deflector. To account for spatial blending and extract less contaminated and higher signal-to-noise ratio (S/N) 1D spectra of the deflectors, a forward modeling method has been implemented. From the extracted spectra, we have measured redshifts using prominent absorption lines and single aperture velocity dispersions using the penalized pixel fitting code pPXF. In this paper, we report the redshifts and single aperture velocity dispersions of eight lens galaxies - J0147+4630, B0445+123, B0631+519, J0659+1629, J0818-2613, J0924+0219, J1433+6007, and J1817+2729. Among these systems, six do not have previously measured velocity dispersions; for the other two, our measurements are consistent with previously reported values. Additionally, we have measured the previously unknown redshifts of the deflectors in J0818-2613 and J1817+2729 to be $0.866\pm 0.002$ and $0.408\pm 0.002$, respectively.

13 pages, 6 figures, 3 tables; accepted in A&A

References in corpus (20)

• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The Megamaser Cosmology Project. XIII. Combined Hubble constant constraints
• Fully-Automated Reduction of Longslit Spectroscopy with the Low Resolution Imaging Spectrometer at Keck Observatory
• H0LiCOW IV. Lens mass model of HE 0435-1223 and blind measurement of its time-delay distance for cosmology
• The Hubble Constant from Infrared Surface Brightness Fluctuation Distances
• H0LiCOW III. Quantifying the effect of mass along the line of sight to the gravitational lens HE 0435-1223 through weighted galaxy counts
• COSMOGRAIL XVI: Time delays for the quadruply imaged quasar DES J0408-5354 with high-cadence photometric monitoring
• Multi-wavelength study of the gravitational lens system RXS J1131-1231: III. Long slit spectroscopy: micro-lensing probes the QSO structure
• Over-constrained Gravitational Lens Models and the Hubble Constant
• Gravitationally lensed quasars in Gaia -- IV. 150 new lenses, quasar pairs, and projected quasars
• STRIDES: Automated uniform models for 30 quadruply imaged quasars
• On the Choice of Lens Density Profile in Time Delay Cosmography
• TDCOSMO. IX. Systematic comparison between lens modelling software programs: time delay prediction for WGD 2038-4008
• TDCOSMO. VII. Boxyness/discyness in lensing galaxies : Detectability and impact on $H_0$
• Doubly imaged quasar SDSS J1515+1511: time delay and lensing galaxies
• TDCOSMO VIII: A key test of systematics in the hierarchical method of time-delay cosmography
• Accurate spectroscopic redshift of the multiply lensed quasar PSOJ0147 from the Pan-STARRS survey
• First black hole mass estimation for the quadruple lensed system WGD2038-4008
• Gravitational Lens System PS J0147+4630 (Andromeda's Parachute): Main Lensing Galaxy and Optical Variability of the Quasar Images

Cited by in corpus (4)

• El Gordo needs El Anzuelo: Probing the structure of cluster members with multi-band extended arcs in JWST data
• HOLISMOKES -- XVIII. Cosmology with strongly lensed type II supernovae: Effects of instrumental setups on $H_0$
• New Dynamical Measurements from a Lensed Quasar Sample: Joint Analysis Constrains the Mass Profile Evolution of Lens Galaxies
• Time Delay Cosmography: Analysis of Quadruply Lensed QSO SDSSJ1433 from Wendelstein Observatory