A Caltech Library Service

A semi-analytic study of self-interacting dark-matter haloes with baryons

Jiang, Fangzhou and Benson, Andrew and Hopkins, Philip F. and Slone, Oren and Lisanti, Mariangela and Kaplinghat, Manoj and Peter, Annika H. G. and Zeng, Zhichao Carton and Du, Xiaolong and Yang, Shengqi and Shen, Xuejian (2022) A semi-analytic study of self-interacting dark-matter haloes with baryons. . (Unpublished)

[img] PDF - Submitted Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


We combine the isothermal Jeans model and the model of adiabatic halo contraction into a simple semi-analytic procedure for computing the density profile of self-interacting dark-matter (SIDM) haloes with the gravitational influence from the inhabitant galaxies. We show that the model agrees well with cosmological SIDM simulations over the entire core-forming stage and up to the onset of gravothermal core-collapse. Using this model, we show that the halo response to baryons is more diverse in SIDM than in CDM and depends sensitively on galaxy size, a desirable link in the context of the structural diversity of bright dwarf galaxies. The fast speed of the method facilitates analyses that would be challenging for numerical simulations -- notably, 1) we quantify the SIDM halo response as functions of the baryonic properties, on a fine mesh grid spanned by the baryon-to-total-mass ratio, M_b/Mᵥᵢᵣ, and galaxy compactness, r_(1/2)/Rᵥᵢᵣ; 2) we show with high statistical precision that for typical Milky-Way-like systems, the SIDM profiles are similar to their CDM counterparts; and 3) we delineate the regime of gravothermal core-collapse in the M_b/Mᵥᵢᵣ - r_(1/2)/Rᵥᵢᵣ space, for a given cross section and a given halo concentration. Finally, we compare the isothermal Jeans model with the more sophisticated gravothermal fluid model, and show that the former yields faster core formation and agrees better with cosmological simulations. We attribute the difference to whether the target CDM halo is used as a boundary condition or as the initial condition for the gravothermal evolution, and thus comment on possible future improvements of the fluid model. We have made our programs for the model publicly available at

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper ItemCode
Jiang, Fangzhou0000-0001-6115-0633
Benson, Andrew0000-0001-5501-6008
Hopkins, Philip F.0000-0003-3729-1684
Slone, Oren0000-0002-5999-106X
Lisanti, Mariangela0000-0002-8495-8659
Kaplinghat, Manoj0000-0001-8555-0164
Peter, Annika H. G.0000-0002-8040-6785
Zeng, Zhichao Carton0000-0002-6008-5144
Shen, Xuejian0000-0002-6196-823X
Additional Information:Attribution 4.0 International (CC BY 4.0). We thank Ethan Nadler, Maya Silverman, Igor Palubski, and Dylan Folsom for helpful general discussions. FJ is partially supported by the Troesh Scholarship from the California Institute of Technology. AB, AHGP, ZCZ, and XD are supported in part by the NASA Astrophysics Theory Program under grant 80NSSC18K1014. ML and OS are supported by the DOE under Award Number DE-SC0007968 and the Binational Science Foundation (grant No. 2018140).
Funding AgencyGrant Number
Troesh ScholarshipUNSPECIFIED
Department of Energy (DOE)DE-SC0007968
Binational Science Foundation (USA-Israel)2018140
Subject Keywords:galaxies: dwarf – galaxies: evolution – galaxies: haloes – galaxies: structure
Record Number:CaltechAUTHORS:20220816-222011684
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:116332
Deposited By: George Porter
Deposited On:18 Aug 2022 19:56
Last Modified:18 Aug 2022 19:56

Repository Staff Only: item control page