Dwarf galaxy halo masses from spectroscopic and photometric lensing in DESI and DES

Journal Article · Wed Sep 24 00:00:00 EDT 2025 · No journal information

OSTI ID:3018648

Treiber, Helena ^[1]; Amon, Alexandra ^[1]; Wechsler, Risa H. ^[2]; Manwadkar, Viraj ^[2]; Myles, Justin ^[1]; Hahn, ChangHoon ^[3]; Hearin, Andrew ^[4]; Heydenreich, Sven ^[5]; Saintonge, Amélie ^[6]; Saraf, Manasvee ^[6]; Aguilar, Jessica Nicole ^[7]; Ahlen, Steven ^[8]; Anand, Abhijeet ^[7]; Bianchi, Davide ^[9]; Brooks, David ^[6]; Castander, Francisco Javier ^[10]; Claybaugh, Todd ^[7]; Cooper, Andrew P. ^[11]; Cuceu, Andrei ^[7]; de la Macorra, Axel ^[12] ; Dey, Biprateep ^[13]; Forero-Romero, Jaime E. ^[14]; Gaztañaga, Enrique ^[15]; Gontcho A. Gontcho, Satya ^[16]; Gutierrez, Gaston ^[17]; Huterer, Dragan ^[18]; Joyce, Dick ^[19]; Juneau, Stephanie ^[19]; Kremin, Anthony ^[7]; Landriau, Martin ^[7]; Le Guillou, Laurent ^[20]; Manera, Marc ^[21]; Meisner, Aaron ^[19]; Miquel, Ramon ^[22]; Moustakas, John ^[23]; Nadathur, Seshadri ^[24]; Percival, Will J. ^[25]; Prada, Francisco ^[26]; Pérez-Ràfols, Ignasi ^[27]; Rossi, Graziano ^[28]; Sanchez, Eusebio ^[29]; Schlegel, David ^[7]; Schubnell, Michael ^[18]; Silber, Joseph Harry ^[7]; Sprayberry, David ^[19]; Tarlé, Gregory ^[18]; Weaver, Benjamin Alan ^[19]; Zhou, Rongpu ^[7]; Zou, Hu ^[30]

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1. Princeton U., Astrophys. Sci. Dept.
2. KIPAC, Menlo Park; SLAC
3. Arizona U., Astron. Dept. - Steward Observ.
4. Argonne
5. UC, Santa Cruz
6. University Coll. London
7. LBL, Berkeley
8. Boston U.
9. Milan U.; Brera Observ.
10. Barcelona, IEEC; ICE, Bellaterra
11. Taiwan, Natl. Tsing Hua U.
12. UNAM, Mexico
13. Toronto U., Astron. Dept.; Pittsburgh U.
14. Andes U., Bogota
15. Barcelona, IEEC; Portsmouth U., ICG; ICE, Bellaterra
16. LBL, Berkeley; Virginia U.
17. Fermilab
18. Michigan U.; KEK, Tsukuba; Hiroshima Shudo U.
19. Natl. Solar Observ., Tucson
20. LPNHE, Paris
21. Barcelona, IFAE; Barcelona, Autonoma U.
22. ICREA, Barcelona; Barcelona, IFAE
23. Siena Coll., Loudonville
24. Portsmouth U., ICG
25. Waterloo U.; Perimeter Inst. Theor. Phys.
26. Granada U., Theor. Phys. Astrophys.
27. Barcelona, Polytechnic U.
28. Sejong U.
29. Madrid, CIEMAT
30. Beijing Observ.

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.

• Research Organization: Granada U., Theor. Phys. Astrophys.; Virginia U.; Madrid, CIEMAT; Arizona U., Astron. Dept. - Steward Observ.; Natl. Solar Observ., Tucson; Boston U.; ICE, Bellaterra; Hiroshima Shudo U.; SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); University Coll. London; ICREA, Barcelona; Taiwan, Natl. Tsing Hua U.; Pittsburgh U.; Barcelona, Autonoma U.; Perimeter Inst. Theor. Phys.; Brera Observ.; Argonne National Laboratory (ANL), Argonne, IL (United States); Michigan U.; UC, Santa Cruz; Sejong U.; Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Toronto U., Astron. Dept.; Siena Coll., Loudonville; UNAM, Mexico; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Andes U., Bogota; KEK, Tsukuba; Waterloo U.; Barcelona, IEEC; LPNHE, Paris; Beijing Observ.; Princeton U., Astrophys. Sci. Dept.; Milan U.; Barcelona, Polytechnic U.; Portsmouth U., ICG; Barcelona, IFAE
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: 89243024CSC000002
• OSTI ID: 3018648
• Report Number(s): FERMILAB-PUB-25-0739-PPD; oai:inspirehep.net:2973455; arXiv:2509.20434
• Journal Information: No journal information, Journal Name: No journal information
• Country of Publication: United States
• Language: English