_version_ 1866909843249430528
author Treiber, Helena
Amon, Alexandra
Wechsler, Risa H.
Manwadkar, Viraj
Myles, Justin
Hahn, ChangHoon
Hearin, Andrew
Heydenreich, Sven
Saintonge, Amélie
Saraf, Manasvee
Aguilar, Jessica Nicole
Ahlen, Steven
Anand, Abhijeet
Bianchi, Davide
Brooks, David
Castander, Francisco Javier
Claybaugh, Todd
Cooper, Andrew P.
Cuceu, Andrei
de la Macorra, Axel
Dey, Biprateep
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Huterer, Dragan
Joyce, Dick
Juneau, Stephanie
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Nadathur, Seshadri
Percival, Will J.
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Silber, Joseph Harry
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zhou, Rongpu
Zou, Hu
author_facet Treiber, Helena
Amon, Alexandra
Wechsler, Risa H.
Manwadkar, Viraj
Myles, Justin
Hahn, ChangHoon
Hearin, Andrew
Heydenreich, Sven
Saintonge, Amélie
Saraf, Manasvee
Aguilar, Jessica Nicole
Ahlen, Steven
Anand, Abhijeet
Bianchi, Davide
Brooks, David
Castander, Francisco Javier
Claybaugh, Todd
Cooper, Andrew P.
Cuceu, Andrei
de la Macorra, Axel
Dey, Biprateep
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Huterer, Dragan
Joyce, Dick
Juneau, Stephanie
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Nadathur, Seshadri
Percival, Will J.
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Silber, Joseph Harry
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zhou, Rongpu
Zou, Hu
contents We present the most precise and lowest-mass weak lensing measurements of dwarf galaxies to date, enabled by spectroscopic lenses from the Dark Energy Spectroscopic Instrument (DESI) and photometric lenses from the Dark Energy Survey (DES) calibrated with DESI redshifts. Using DESI spectroscopy from the first data release, we construct clean samples of galaxies with median stellar masses $\log_{10}(M_*/M_{\odot})=8.3-10.1$ and measure their weak lensing signals with sources from DES, KiDS, and SDSS, achieving detections with $S/N$ up to 14 for dwarf galaxies ($\log_{10}(M_*/M_{\odot})<$9.25) -- opening up a new regime for lensing measurements of low-mass systems. Leveraging DES photometry calibrated with DESI, we extend to a photometric dwarf sample of over 700,000 galaxies, enabling robust lensing detections of dwarf galaxies with combined $S/N=38$ and a significant measurement down to $\log_{10}(M_*/M_{\odot})=8.0$. We show that the one-halo regime (scales $\lesssim 0.15h^{-1}\rm Mpc$) is insensitive to various systematic and sample selection effects, providing robust halo mass estimates, while the signal in the two-halo regime depends on galaxy color and environment. These results demonstrate that DESI already enables precise dwarf lensing measurements, and that calibrated photometric samples extend this capability. Together, they pave the way for novel constraints on dwarf galaxy formation and dark matter physics with upcoming surveys like the Vera C. Rubin Observatory's LSST.
format Preprint
id arxiv_https___arxiv_org_abs_2509_20434
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dwarf galaxy halo masses from spectroscopic and photometric lensing in DESI and DES
Treiber, Helena
Amon, Alexandra
Wechsler, Risa H.
Manwadkar, Viraj
Myles, Justin
Hahn, ChangHoon
Hearin, Andrew
Heydenreich, Sven
Saintonge, Amélie
Saraf, Manasvee
Aguilar, Jessica Nicole
Ahlen, Steven
Anand, Abhijeet
Bianchi, Davide
Brooks, David
Castander, Francisco Javier
Claybaugh, Todd
Cooper, Andrew P.
Cuceu, Andrei
de la Macorra, Axel
Dey, Biprateep
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Huterer, Dragan
Joyce, Dick
Juneau, Stephanie
Kremin, Anthony
Landriau, Martin
Guillou, Laurent Le
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Nadathur, Seshadri
Percival, Will J.
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schlegel, David
Schubnell, Michael
Silber, Joseph Harry
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zhou, Rongpu
Zou, Hu
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
We present the most precise and lowest-mass weak lensing measurements of dwarf galaxies to date, enabled by spectroscopic lenses from the Dark Energy Spectroscopic Instrument (DESI) and photometric lenses from the Dark Energy Survey (DES) calibrated with DESI redshifts. Using DESI spectroscopy from the first data release, we construct clean samples of galaxies with median stellar masses $\log_{10}(M_*/M_{\odot})=8.3-10.1$ and measure their weak lensing signals with sources from DES, KiDS, and SDSS, achieving detections with $S/N$ up to 14 for dwarf galaxies ($\log_{10}(M_*/M_{\odot})<$9.25) -- opening up a new regime for lensing measurements of low-mass systems. Leveraging DES photometry calibrated with DESI, we extend to a photometric dwarf sample of over 700,000 galaxies, enabling robust lensing detections of dwarf galaxies with combined $S/N=38$ and a significant measurement down to $\log_{10}(M_*/M_{\odot})=8.0$. We show that the one-halo regime (scales $\lesssim 0.15h^{-1}\rm Mpc$) is insensitive to various systematic and sample selection effects, providing robust halo mass estimates, while the signal in the two-halo regime depends on galaxy color and environment. These results demonstrate that DESI already enables precise dwarf lensing measurements, and that calibrated photometric samples extend this capability. Together, they pave the way for novel constraints on dwarf galaxy formation and dark matter physics with upcoming surveys like the Vera C. Rubin Observatory's LSST.
title Dwarf galaxy halo masses from spectroscopic and photometric lensing in DESI and DES
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2509.20434