3 research outputs found
Noema formIng Cluster survEy (NICE): Discovery of a starbursting galaxy group with a radio-luminous core at z=3.95
The study of distant galaxy groups and clusters at the peak epoch of star
formation is limited by the lack of a statistically and homogeneously selected
and spectroscopically confirmed sample. Recent discoveries of concentrated
starburst activities in cluster cores have opened a new window to hunt for
these structures based on their integrated IR luminosities. Hereby we carry out
the large NOEMA (NOrthern Extended Millimeter Array) program targeting a
statistical sample of infrared-luminous sources associated with overdensities
of massive galaxies at z>2, the Noema formIng Cluster survEy (NICE). We present
the first result from the ongoing NICE survey, a compact group at z=3.95 in the
Lockman Hole field (LH-SBC3), confirmed via four massive (M_star>10^10.5M_sun)
galaxies detected in CO(4-3) and [CI](1-0) lines. The four CO-detected members
of LH-SBC3 are distributed over a 180 kpc physical scale, and the entire
structure has an estimated halo mass of ~10^13Msun and total star formation
rate (SFR) of ~4000Msun/yr. In addition, the most massive galaxy hosts a
radio-loud AGN with L_1.4GHz, rest = 3.0*10^25W/Hz. The discovery of LH-SBC3
demonstrates the feasibility of our method to efficiently identify high-z
compact groups or forming cluster cores. The existence of these starbursting
cluster cores up to z~4 provides critical insights into the mass assembly
history of the central massive galaxies in clusters.Comment: 7 pages, 7 figures, submitted to A&
ALMA FIR View of Ultra High-redshift Galaxy Candidates at 11-17: Blue Monsters or Low- Red Interlopers?
We present ALMA Band 7 observations of a remarkably bright galaxy candidate at = (=), S5-z17-1, identified in JWST Early Release Observation data of Stephen's Quintet. We do not detect the dust continuum at 866 m, ruling out the possibility that S5-z17-1 is a low- dusty starburst with a star-formation rate (SFR) of yr. We detect a 5.1 line feature at GHz exactly coinciding with the JWST source position, with a 2% likelihood of the signal being spurious. The most likely line identification would be [OIII]52m at or [CII]158m at , whose line luminosities do not violate the non-detection of the dust continuum in both cases. Together with three other 11-13 candidate galaxies recently observed with ALMA, we conduct a joint ALMA and JWST spectral energy distribution (SED) analysis and find that the high- solution at 11-17 is favored in every candidate as a very blue (UV continuum slope of ) and luminous ( [24:21]) system. Still, we find in some candidates that reasonable SED fits ( ) are reproduced by type-II quasar and/or quiescent galaxy templates with strong emission lines at -5, where such populations predicted from their luminosity functions and EW([OIII]+H) distributions are abundant in survey volumes used for the 11-17 candidates. While these recent ALMA observation results have strengthened the likelihood of the high- solutions, lower- possibilities are not completely ruled out in some of the 11-17 candidates
ALMA FIR View of Ultra High-redshift Galaxy Candidates at 11-17: Blue Monsters or Low- Red Interlopers?
We present ALMA Band 7 observations of a remarkably bright galaxy candidate at = (=), S5-z17-1, identified in JWST Early Release Observation data of Stephen's Quintet. We do not detect the dust continuum at 866 m, ruling out the possibility that S5-z17-1 is a low- dusty starburst with a star-formation rate (SFR) of yr. We detect a 5.1 line feature at GHz exactly coinciding with the JWST source position, with a 2% likelihood of the signal being spurious. The most likely line identification would be [OIII]52m at or [CII]158m at , whose line luminosities do not violate the non-detection of the dust continuum in both cases. Together with three other 11-13 candidate galaxies recently observed with ALMA, we conduct a joint ALMA and JWST spectral energy distribution (SED) analysis and find that the high- solution at 11-17 is favored in every candidate as a very blue (UV continuum slope of ) and luminous ( [24:21]) system. Still, we find in some candidates that reasonable SED fits ( ) are reproduced by type-II quasar and/or quiescent galaxy templates with strong emission lines at -5, where such populations predicted from their luminosity functions and EW([OIII]+H) distributions are abundant in survey volumes used for the 11-17 candidates. While these recent ALMA observation results have strengthened the likelihood of the high- solutions, lower- possibilities are not completely ruled out in some of the 11-17 candidates