5 results
Search Results
2. Examining the self-interaction of dark matter through central cluster galaxy offsets.
- Author
-
Cross, D, Thoron, G, Jeltema, T E, Swart, A, Hollowood, D L, Adhikari, S, Bocquet, S, Eiger, O, Everett, S, Jobel, J, Laubner, D, McDaniel, A, Aguena, M, Alves, O, Andrade-Oliveira, F, Bacon, D, Bertin, E, Brooks, D, Burke, D L, and Carnero Rosell, A
- Subjects
- *
DARK matter , *DARK energy , *GALAXY clusters , *ASTRONOMICAL surveys , *GALACTIC redshift , *CLUSTER sampling , *X-rays - Abstract
While collisionless cold dark matter models have been largely successful in explaining a wide range of observational data, some tensions still exist, and it remains possible that dark matter possesses a non-negligible level of self-interactions. In this paper, we investigate a possible observable consequence of self-interacting dark matter: offsets between the central galaxy and the centre of mass of its parent halo. We examine 23 relaxed galaxy clusters in a redshift range of 0.1–0.3 drawn from clusters in the Dark Energy Survey and the Sloan Digital Sky Survey which have archival Chandra X-ray data of sufficient depth for centre and relaxation determination. We find that most clusters in our sample show non-zero offsets between the X-ray centre, taken to be the centroid within the cluster core, and the central galaxy position. All of the measured offsets are larger, typically by an order of magnitude, than the uncertainty in the X-ray position due to Poisson noise. In all but six clusters, the measured offsets are also larger than the estimated, combined astrometric uncertainties in the X-ray and optical positions. A more conservative cut on concentration to select relaxed clusters marginally reduces but does not eliminate the observed offset. With our more conservative sample, we find an estimated median X-ray to central galaxy offset of |$\mu = 6.0 ^{+ 1.4}_{- 1.5}$| kpc. Comparing to recent simulations, this distribution of offsets is consistent with some level of dark matter self-interaction, though further simulation work is needed to place constraints. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. The X-ray invisible Universe. A look into the haloes undetected by eROSITA.
- Author
-
Popesso, P, Biviano, A, Bulbul, E, Merloni, A, Comparat, J, Clerc, N, Igo, Z, Liu, A, Driver, S, Salvato, M, Brusa, M, Bahar, Y E, Malavasi, N, Ghirardini, V, Robotham, A, Liske, J, and Grandis, S
- Subjects
- *
GALACTIC halos , *SURFACE brightness (Astronomy) , *ACTIVE galactic nuclei , *X-rays , *GAS distribution , *X-ray detection ,UNIVERSE - Abstract
The paper presents the analysis of optically selected GAMA groups and clusters in the SRG/eROSITA X-ray map of eROSITA Final Equatorial Depth Survey, in the halo mass range 1013−5 × 1014 M⊙ and at z < 0.2. All X-ray detections have a clear GAMA counterpart, but most of the GAMA groups in the halo mass range 1013−1014 M⊙ remain undetected. We compare the X-ray surface brightness profiles of the eROSITA detected groups with the mean stacked profile of the undetected low-mass haloes at fixed halo mass. Overall, we find that the undetected groups exhibit less concentrated X-ray surface brightness, dark matter, and galaxy distributions with respect to the X-ray-detected haloes. The mean gas mass fraction profiles are consistent in the two samples within 1.5σ, indicating that the gas follows the dark matter profile. The low-mass concentration and the magnitude gap indicate that these systems are young. They reside with a higher probability in filaments while X-ray-detected groups favour the nodes of the Cosmic Web. Because of the lower central emission, the undetected systems tend to be X-ray underluminous at fixed halo mass and to lie below the LX − M halo relation. Interestingly, the X-ray-detected systems inhabiting the nodes scatter the less around the relation, while those in filaments tend to lie below it. We do not observe any strong relationship between the system X-ray appearance and the active galactic nucleus (AGN) activity. We cannot exclude the role of the past AGN feedback in affecting the gas distribution over the halo lifetime. However, the data suggests that the observed differences might be related to the halo assembly bias. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. MaNGA DynPop – IV. Stacked total density profile of galaxy groups and clusters from combining dynamical models of integral-field stellar kinematics and galaxy–galaxy lensing.
- Author
-
Wang, Chunxiang, Li, Ran, Zhu, Kai, Shan, Huanyuan, Xu, Weiwei, Cappellari, Michele, Gao, Liang, Li, Nan, Lu, Shengdong, Mao, Shude, Yao, Ji, and Xie, Yushan
- Subjects
- *
STELLAR initial mass function , *GALAXY clusters , *DARK matter , *STELLAR mass , *KINEMATICS , *DENSITY - Abstract
We present the measurement of total and stellar/dark matter decomposed mass density profile around a sample of galaxy groups and clusters with dynamical masses derived from integral-field stellar kinematics from the MaNGA survey in Paper I and weak lensing derived from the DECaLS imaging survey. Combining the two data sets enables accurate measurement of the radial density distribution from several kpc to Mpc scales. Intriguingly, we find that the excess surface density derived from stellar kinematics in the inner region cannot be explained by simply adding an NFW dark matter halo extrapolated from lensing measurement at a larger scale to a stellar mass component derived from the NASA-Sloan Atlas (NSA) catalogue. We find that a good fit to both data sets requires a stellar mass normalization about three times higher than that derived from the NSA catalogue, which would require an unrealistically too-heavy initial mass function for stellar mass estimation. If we keep the stellar mass normalization to that of the NSA catalogue but allow a varying inner dark matter density profile, we obtain an asymptotic slope of γgnfw = |$1.82_{-0.25}^{+0.15}$| and γgnfw = |$1.48_{-0.41}^{+0.20}$| for the group bin and the cluster bin, respectively, significantly steeper than the NFW case. We also compare the total mass inner density slopes with those from TNG300 and find that the values from the simulation are lower than the observation by about 2σ level. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Correction to: Redshift drift and strong gravitational lensing.
- Author
-
Helbig, Phillip
- Subjects
- *
GRAVITATIONAL lenses , *REDSHIFT , *DARK matter , *GALAXY clusters , *PHYSICAL cosmology , *HUBBLE constant - Abstract
The article titled "Correction to: Redshift drift and strong gravitational lensing" acknowledges a mistake made in a recent paper by the author. The mistake relates to the measurement of the Hubble constant using the difference in redshift between images of a gravitational-lens system. The author clarifies that the redshift difference can still be used to measure other cosmological parameters without knowledge of the Hubble constant. The rest of the paper remains unaffected, discussing various aspects of standard cosmology and gravitational lensing. No new data is associated with the article. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.