H-ATLAS: a candidate high redshift cluster/protocluster of star-forming galaxies

Clements, D. L.; Braglia, F. G.; Petitpas, G.; Greenslade, J.; Cooray, Asantha; Valiante, Elisabetta; Zotti, G. de; O’Halloran, B.; Holdship, Jonathan; Morris, Brett M.; Pérez-Fournón, I.; Herranz, D.; Riechers, Dominik A.; Baes, M.; Bremer, M. N.; Bourne, N.; Dannerbauer, H.; Dariush, Aliakbar; Dunne, L.; Eales, Steve; Fritz, J.; González‐Nuevo, J.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Leeuw, L. L.; Maddox, Steve; Michałowski, M. J.; Negrello, M.; Omont, A.; Oteo, I.; Serjeant, S.; Valtchanov, I.; Vieira, J. D.; Wardlow, J. L.; Werf, P. van der

doi:10.1093/mnras/stw1224

Cited by 34 publications

(34 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If these observed Herschel overdensities are coherent structures, their total IR luminosity would peak at 4 × 10 13 L , or in terms of an SFR, at 4 × 10 3 M yr −1 , that is the equivalent of ten typical sources making up the overdensity. We note that a parallel study of Planck compact sources overlapping within already existing Herschel fields also finds 27 proto-cluster candidates (Greenslade et al 2018); for earlier such samples see also Herranz et al (2013), Clements et al (2014), andClements et al (2016).…”

Section: Figmentioning

confidence: 52%

Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4−57.5

Kneißl

Polletta

Martinache

et al. 2019

A&A

View full text Add to dashboard Cite

Galaxy clusters at high redshift are key targets for understanding matter assembly in the early Universe, yet they are challenging to locate. A sample of more than 2000 high-z candidate structures has been found using Planck's all-sky submillimetre maps, and a sub-set of 234 have been followed up with Herschel-SPIRE, which showed that the emission can be attributed to large overdensities of dusty star-forming galaxies. As a next step, we need to resolve and characterise the individual galaxies giving rise to the emission seen by Planck and Herschel, and to find out whether they constitute the progenitors of present-day, massive galaxy clusters. Thus, we targeted the eight brightest Herschel-SPIRE sources in the centre of the Planck peak PLCK G073.4−57.5 using ALMA at 1.3 mm, and complemented these observations with multi-wavelength data from Spitzer-IRAC, CFHT-WIRCam in the J and K s bands, and JCMT's SCUBA-2 instrument. We detected a total of 18 millimetre galaxies brighter than 0.3 mJy within the 2.4 arcmin 2 ALMA pointings, corresponding to an ALMA source density 8-30 times higher than average background estimates and larger than seen in typical 'proto-cluster' fields. We were able to match all but one of the ALMA sources to a near infrared (NIR) counterpart. The four most significant SCUBA-2 sources are not included in the ALMA pointings, but we find an 8 σ stacking detection of the ALMA sources in the SCUBA-2 map at 850 µm. We derive photometric redshifts, infrared (IR) luminosities, star-formation rates (SFRs), stellar masses (M), dust temperatures, and dust masses for all of the ALMA galaxies. Photometric redshifts identify two groups each of five sources, concentrated around z 1.5 and 2.4. The two groups show two 'red sequences', that is similar near-IR [3.6] − [4.5] colours and different J − K s colours. The majority of the ALMA-detected galaxies are on the SFR versus M main sequence (MS), and half of the sample is more massive than the characteristic M * at the corresponding redshift. We find that the z 1.5 group has total SFR = 840 +120 −100 M yr −1 and M = 5.8 +1.7 −2.4 × 10 11 M , and that the z 2.4 group has SFR = 1020 +310 −170 M yr −1 and M = 4.2 +1.5 −2.1 × 10 11 M , but the latter group is more scattered in stellar mass and around the MS. Serendipitous CO line detections in two of the galaxies appear to match their photometric redshifts at z = 1.54. We performed an analysis of star-formation efficiencies (SFEs) and CO-and mm-continuum-derived gas fractions of our ALMA sources, combined with a sample of 1 < z < 3 cluster and proto-cluster members, and observed trends in both quantities with respect to stellar masses and in comparison to field galaxies. A dedicated Herschel (Pilbratt et al. 2010) follow-up programme with the SPIRE instrument for 234 Planck targets (Planck Collab. XXXVII 2015) found a significant excess of 'red' sources (where red means S 350 / S 250 > 0.7 and S 500 / S 350 > 0.6, which is consistent with z > ∼ 2 SFGs), in comparison to reference SPIRE fields. Assuming a single com...

show abstract

Section: Figmentioning

confidence: 52%

Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4−57.5

Kneißl

Polletta

Martinache

et al. 2019

A&A

View full text Add to dashboard Cite

show abstract

“…After the above selection criteria, some of the remaining Planck compact sources (Herranz et al 2013) were targeted with other observations (Clements et al 2014(Clements et al , 2016.…”

Section: Selection Of Candidate Protoclustersmentioning

confidence: 99%

SCUBA-2 observations of candidate starbursting protoclusters selected by Planck and Herschel-SPIRE

Cheng

Clements

Greenslade

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present SCUBA-2 850-µm observations of 13 candidate starbursting protoclusters selected using Planck and Herschel data. The cumulative number counts of the 850-µm sources in 9/13 of these candidate protoclusters show significant overdensities compared to the field, with the probability <10 −2 assuming the sources are randomly distributed in the sky. Using the 250-, 350-, 500-and 850-µm flux densities, we estimate the photometric redshifts of individual SCUBA-2 sources by fitting spectral energy distribution (SED) templates with an MCMC method. The photometric redshift distribution, peaking at 2 < z < 3, is consistent with that of known z > 2 protoclusters and the peak of the cosmic star-formation rate density (SFRD). We find that the 850µm sources in our candidate protoclusters have infrared luminosities of L IR 10 12 L and star-formation rates of SFR=(500-1,500)M yr −1 . By comparing with results in the literature considering only Herschel photometry, we conclude that our 13 candidate protoclusters can be categorised into four groups: six of them being high-redshift starbursting protoclusters, one being a lower-redshift cluster/protocluster, three being protoclusters that contain lensed DSFG(s) or are rich in 850-µm sources, and three regions without significant Herschel or SCUBA-2 source overdensities. The total SFRs of the candidate protoclusters are found to be comparable or higher than those of known protoclusters, suggesting our sample contains some of the most extreme protocluster population. We infer that cross-matching Planck and Herschel data is a robust method for selecting candidate protoclusters with overdensities of 850-µm sources.

show abstract

“…Here we perform the statistical study of the IR properties of the protoclusters by using the archival IR all sky maps. Lately, plausible clusters of DSFGs at z = 2 to 4 detected as point sources on Planck high frequency instrument (HFI) sky images has been reported (e.g., Clements et al 2014Clements et al , 2016Greenslade et al 2018). The spatial resolution and detection limit of the P lanck HFI images are too low to discretely identify galaxies at high redshift; however they are useful to evaluate the average total sum flux of protocluster galaxies, though it is difficult to individually detect protoclusters at z ∼ 4.…”

Section: Introductionmentioning

confidence: 99%

Planck Far-infrared Detection of Hyper Suprime-Cam Protoclusters at z ∼ 4: Hidden AGN and Star Formation Activity

Kubo

Toshikawa

Kashikawa

et al. 2019

ApJ

View full text Add to dashboard Cite

We perform a stacking analysis of Planck, AKARI, Infrared Astronomical Satellite (IRAS), Widefield Infrared Survey Eplorer (W ISE), and Herschel images of the largest number of (candidate) protoclusters at z ∼ 3.8 selected from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Stacking the images of the 179 candidate protoclusters, the combined infrared (IR) emission of the protocluster galaxies in the observed 12 − 850 µm wavelength range is successfully detected with > 5σ significance (at P lanck). This is the first time that the average IR spectral energy distribution (SED) of a protocluster has been constrained at z ∼ 4. The observed IR SEDs of the protoclusters exhibit significant excess emission in the mid-IR compared to that expected from typical star-forming galaxies (SFGs). They are reproduced well using SED models of intense starburst galaxies with warm/hot dust heated by young stars, or by a population of active galactic nuclei (AGN)/SFG composites. For the pure star-forming model, a total IR (from 8 to 1000 µm) luminosity of 19.3 +0.6 −4.2 × 10 13 L and a star formation rate (SFR) of 16.3 +1.0 −7.8 × 10 3 M yr −1 are found whereas for the AGN/SFG composite model, 5.1 +2.5 −2.5 × 10 13 L and 2.1 +6.3 −1.7 × 10 3 M yr −1 are found. Uncertainty remaining in the total SFRs; however, the IR luminosities of the most massive protoclusters are likely to continue increasing up to z ∼ 4. Meanwhile, no significant IR flux excess is observed around optically selected QSOs at similar redshifts, which confirms previous results. Our results suggest that the z ∼ 4 protoclusters trace dense, intensely star-forming environments that may also host obscured AGNs missed by the selection in the optical.

show abstract

H-ATLAS: a candidate high redshift cluster/protocluster of star-forming galaxies

Cited by 34 publications

References 78 publications

Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4−57.5

Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4−57.5

SCUBA-2 observations of candidate starbursting protoclusters selected by Planck and Herschel-SPIRE

Planck Far-infrared Detection of Hyper Suprime-Cam Protoclusters at z ∼ 4: Hidden AGN and Star Formation Activity

Contact Info

Product

Resources

About