# THE CORE-CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF MASS LOSS

## Abstract

The core-cusp problem remains as one of the unsolved discrepancies between observations and theories predicted by the standard paradigm of cold dark matter (CDM) cosmology. To solve this problem, we perform N-body simulations to study the nonlinear response of CDM halos to the variance of the gravitational potential induced by gas removal from galaxy centers. In this study, we focus on the timescale of the gas ejection, which is strongly correlated with stellar activities, and demonstrate that it is one of the key factors in determining the dynamical response of CDM halos. The results of simulations show that the power-law index of the mass-density profile of the dark matter (DM) halo is correlated with the timescale of the mass loss and it is flatter when the mass loss occurs over a short time than when it occurs over a long time. However, it is still larger than typical observational values; in other words, the central cusp remains in the simulations for any mass-loss model. Moreover, for the slow mass-loss case, the final density profile of the DM halo recovers the universal density profiles predicted by the CDM cosmology. Therefore, the mass loss driven by stellar feedback may not be anmore »

- Authors:

- Graduate School of Pure and Applied Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577 (Japan)

- Publication Date:

- OSTI Identifier:
- 21562539

- Resource Type:
- Journal Article

- Journal Name:
- Astrophysical Journal Letters

- Additional Journal Information:
- Journal Volume: 736; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/736/1/L2; Journal ID: ISSN 2041-8205

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; LOSSES; MASS; NONLINEAR PROBLEMS; NONLUMINOUS MATTER; SIMULATION; STELLAR ACTIVITY; MATTER; PHYSICAL PROPERTIES

### Citation Formats

```
Ogiya, Go, and Mori, Masao, E-mail: ogiya@ccs.tsukuba.ac.jp.
```*THE CORE-CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF MASS LOSS*. United States: N. p., 2011.
Web. doi:10.1088/2041-8205/736/1/L2.

```
Ogiya, Go, & Mori, Masao, E-mail: ogiya@ccs.tsukuba.ac.jp.
```*THE CORE-CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF MASS LOSS*. United States. doi:10.1088/2041-8205/736/1/L2.

```
Ogiya, Go, and Mori, Masao, E-mail: ogiya@ccs.tsukuba.ac.jp. Wed .
"THE CORE-CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF MASS LOSS". United States. doi:10.1088/2041-8205/736/1/L2.
```

```
@article{osti_21562539,
```

title = {THE CORE-CUSP PROBLEM IN COLD DARK MATTER HALOS AND SUPERNOVA FEEDBACK: EFFECTS OF MASS LOSS},

author = {Ogiya, Go and Mori, Masao, E-mail: ogiya@ccs.tsukuba.ac.jp},

abstractNote = {The core-cusp problem remains as one of the unsolved discrepancies between observations and theories predicted by the standard paradigm of cold dark matter (CDM) cosmology. To solve this problem, we perform N-body simulations to study the nonlinear response of CDM halos to the variance of the gravitational potential induced by gas removal from galaxy centers. In this study, we focus on the timescale of the gas ejection, which is strongly correlated with stellar activities, and demonstrate that it is one of the key factors in determining the dynamical response of CDM halos. The results of simulations show that the power-law index of the mass-density profile of the dark matter (DM) halo is correlated with the timescale of the mass loss and it is flatter when the mass loss occurs over a short time than when it occurs over a long time. However, it is still larger than typical observational values; in other words, the central cusp remains in the simulations for any mass-loss model. Moreover, for the slow mass-loss case, the final density profile of the DM halo recovers the universal density profiles predicted by the CDM cosmology. Therefore, the mass loss driven by stellar feedback may not be an effective mechanism to flatten the central cusp.},

doi = {10.1088/2041-8205/736/1/L2},

journal = {Astrophysical Journal Letters},

issn = {2041-8205},

number = 1,

volume = 736,

place = {United States},

year = {2011},

month = {7}

}