Categorizing Candidate Galaxy Protoclusters from Planck

Brown, Jonathon; Casey, Caitlin M.; Dannerbauer, H.
Bibliographical reference

American Astronomical Society, AAS Meeting #231, id.#252.07

Advertised on:
1
2018
Number of authors
3
IAC number of authors
1
Citations
0
Refereed citations
0
Description
To better understand how galaxy clusters form, we look at their progenitors which have not yet virialized: protoclusters. We use the Planck Collaboration (2016) published list of 2,151 protocluster candidate sources to explore further characterization as bonafide protoclusters or other extragalactic phenomena. We investigate the correlation of Planck sources with those detected by IRAS and WISE. Less than 1% of sources are detected with IRAS. We hypothesize that these sit at low redshifts, yet their Planck-determined FIR/submm photometric redshifts are evenly distributed out to high-redshifts. We visually inspect WISE imaging to separate sources into those that exhibit overdensities, or “clumps” of sources as possible lower-redshift protoclusters; detection of an overdensity by WISE should also imply sources sit at lower redshifts, yet we also find similar discord between such sources’ FIR/submm photometric redshifts and our conjecture that they are low-redshift sources. The next step in our analysis is to model the spectral energy distributions of Planck sources with WISE and IRAS detections to further refine their redshift constraints.