We present a novel approach to extracting dwarf galaxies from photometric data to measure their average halo mass profile with weak lensing. We characterize their stellar mass and redshift distributions with a spectroscopic calibration sample. By combining the $${\sim} 5000\,\mathrm{deg}^2$$ multiband photometry from the Dark Energy Survey and redshifts from the Satellites Around Galactic Analogs Survey with an unsupervised machine learning method, we select a low-mass galaxy sample spanning redshifts $$z\lt 0.3$$ and divide it into three mass bins. From low to high median mass, the bins contain [146 420, 330 146, 275 028] galaxies and have median stellar masses of $$\log _{10}(M_*/\text{M}_\odot)=\left[8.52\substack{+0.57 -0.76},\, 9.02\substack{+0.50 -0.64},\, 9.49\substack{+0.50 -0.58}\right]$$ . We measure the stacked excess surface mass density profiles, $$\Delta \Sigma (R)$$, of these galaxies using galaxy–galaxy lensing with a signal-to-noise ratio of [14, 23, 28]. Through a simulation-based forward-modelling approach, we fit the measurements to constrain the stellar-to-halo mass relation and find the median halo mass of these samples to be $$\log _{10}(M_{\rm halo}/\text{M}_\odot)$$ = [$$10.67\substack{+0.2 -0.4}$$, $$11.01\substack{+0.14 -0.27}$$, $$11.40\substack{+0.08 -0.15}$$]. The cold dark matter profiles are consistent with NFW (Navarro, Frenk, and White) profiles over scales $${\lesssim} 0.15 \, {h}^{-1}$$ Mpc. We find that $${\sim} 20$$ per cent of the dwarf galaxy sample are satellites. This is the first measurement of the halo profiles and masses of such a comprehensive, low-mass galaxy sample. The techniques presented here pave the way for extracting and analysing even lower mass dwarf galaxies and for more finely splitting galaxies by their properties with future photometric and spectroscopic survey data.
Thornton, Joseph, et al. "The mass profiles of dwarf galaxies from Dark Energy Survey lensing." Monthly Notices of the Royal Astronomical Society, vol. 535, no. 1, Oct. 2024. https://doi.org/10.1093/mnras/stae2040
Thornton, Joseph, Amon, Alexandra, Wechsler, Risa H., Adhikari, Susmita, Mao, Yao-Yuan, Myles, Justin, Geha, Marla, Kallivayalil, Nitya, Tollerud, Erik, & Weiner, Benjamin (2024). The mass profiles of dwarf galaxies from Dark Energy Survey lensing. Monthly Notices of the Royal Astronomical Society, 535(1). https://doi.org/10.1093/mnras/stae2040
Thornton, Joseph, Amon, Alexandra, Wechsler, Risa H., et al., "The mass profiles of dwarf galaxies from Dark Energy Survey lensing," Monthly Notices of the Royal Astronomical Society 535, no. 1 (2024), https://doi.org/10.1093/mnras/stae2040
@article{osti_2475009,
author = {Thornton, Joseph and Amon, Alexandra and Wechsler, Risa H. and Adhikari, Susmita and Mao, Yao-Yuan and Myles, Justin and Geha, Marla and Kallivayalil, Nitya and Tollerud, Erik and Weiner, Benjamin},
title = {The mass profiles of dwarf galaxies from Dark Energy Survey lensing},
annote = {We present a novel approach to extracting dwarf galaxies from photometric data to measure their average halo mass profile with weak lensing. We characterize their stellar mass and redshift distributions with a spectroscopic calibration sample. By combining the ${\sim} 5000\,\mathrm{deg}^2$ multiband photometry from the Dark Energy Survey and redshifts from the Satellites Around Galactic Analogs Survey with an unsupervised machine learning method, we select a low-mass galaxy sample spanning redshifts $z\lt 0.3$ and divide it into three mass bins. From low to high median mass, the bins contain [146 420, 330 146, 275 028] galaxies and have median stellar masses of $\log _{10}(M_*/\text{M}_\odot)=\left[8.52\substack{+0.57 -0.76},\, 9.02\substack{+0.50 -0.64},\, 9.49\substack{+0.50 -0.58}\right]$ . We measure the stacked excess surface mass density profiles, $\Delta \Sigma (R)$, of these galaxies using galaxy–galaxy lensing with a signal-to-noise ratio of [14, 23, 28]. Through a simulation-based forward-modelling approach, we fit the measurements to constrain the stellar-to-halo mass relation and find the median halo mass of these samples to be $\log _{10}(M_{\rm halo}/\text{M}_\odot)$ = [$10.67\substack{+0.2 -0.4}$, $11.01\substack{+0.14 -0.27}$, $11.40\substack{+0.08 -0.15}$]. The cold dark matter profiles are consistent with NFW (Navarro, Frenk, and White) profiles over scales ${\lesssim} 0.15 \, {h}^{-1}$ Mpc. We find that ${\sim} 20$ per cent of the dwarf galaxy sample are satellites. This is the first measurement of the halo profiles and masses of such a comprehensive, low-mass galaxy sample. The techniques presented here pave the way for extracting and analysing even lower mass dwarf galaxies and for more finely splitting galaxies by their properties with future photometric and spectroscopic survey data.},
doi = {10.1093/mnras/stae2040},
url = {https://www.osti.gov/biblio/2475009},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {ISSN 0035-8711},
number = {1},
volume = {535},
place = {United States},
publisher = {Oxford University Press},
year = {2024},
month = {10}}
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
Deutsche Forschungsgemeinschaft; ETH; Fermi National Accelerator Laboratory; Financiadora de Estudos e Projetos; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro; Heising-Simons Foundation; Higher Education Funding Council for England; Lawrence Berkeley National Laboratory; Ministério da Ciência, Tecnologia e Inovação; National Center for Supercomputing Applications; National Science Foundation; National Science Foundation (NSF); SLAC National Accelerator Laboratory; Science and Technology Facilities Council; Stanford University; Texas A&M University; U.S. Department of Energy; USDOE; University of Michigan; University of Nottingham; University of Pennsylvania; University of Portsmouth; University of Sussex
Grant/Contract Number:
AC02-76SF00515
OSTI ID:
2475009
Alternate ID(s):
OSTI ID: 2584779 OSTI ID: 2583354
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 1 Vol. 535; ISSN 1365-2966; ISSN 0035-8711