| Full text | |
| Author(s): |
Ferreras, I
;
Boehm, A.
;
Umetsu, K.
;
Sampaio, V
;
de Carvalho, R. R.
Total Authors: 5
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 519, n. 4, p. 9-pg., 2023-03-01. |
| Abstract | |
Backsplash galaxies are those that traverse and overshoot cluster cores as they fall into these structures. They are affected by environment, and should stand out in contrast to the infalling population. We target galaxies in the vicinity of clusters (R greater than or similar to R-200) and select a sample in projected phase space (PPS), from the compilation of Sampaio et al. based on the Sloan Digital Sky Survey data. We present a statistical analysis, comparing two regions in PPS, with the same projected distance to the cluster but different velocity. The analysis relies on the presence of variations in the stellar population content of backsplash galaxies. We find a lower limit in the fractional contribution of similar to 5 percent with respect to the general sample of infalling galaxies at similar group-centric distance when using single line strength analysis, or similar to 15-30 percent when adopting bivariate distributions. The stellar populations show a subtle but significant difference towards older ages, and a higher fraction of quiescent galaxies. We also compare this set with a general field sample, where a substantially larger difference in galaxy properties is found, with the field sample being consistently younger, metal poorer, and with a lower fraction of quiescent galaxies. Noting that our 'cluster' sample is located outside of the virial radius, we expect this difference to be caused by pre-processing of the infalling galaxies in the overall higher density regions. (AU) | |
| FAPESP's process: | 20/16243-3 - Investigating environmental effects in galaxy evolution: from cosmological simulations to observations |
| Grantee: | Vitor Medeiros Sampaio |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 21/13683-5 - The interplay between internal and environmental quenching mechanisms in central galaxies evolution |
| Grantee: | Vitor Medeiros Sampaio |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |