#MPIfR:
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Wie sich riesige Galaxien nur 1,4 Milliarden Jahre nach dem Urknall bilden konnten
Neue Radiobeobachtungen von molekularem Gas zeigen, wie Dutzende von Galaxien im frühen Universum schnell miteinander verschmelzen.
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https://www.mpifr-bonn.mpg.de/pressemeldungen/2026/massereiche-galaxien-im-fruehen-universum
10.2.2026
#ALMA #APEX #Astronomie #Galaxie #Galaxienhaufen #Gas #Protocluster #Kohlenstoff #Kosmologie #Radioastronomie #SPT234956 #Staub #Sternentstehung #Universum
It’s Saturday morning in Barcelona, and time to post another update relating to the Open Journal of Astrophysics. Since the last update we have published two more papers, taking the count in Volume 7 (2024) up to 47 and the total published by OJAp up to 162. We actually accepted four papers last week, but so far only two final versions have appeared on the arXiv.
The first paper of the most recent pair – published on Friday 14th June – is “Spectroscopic Confirmation of an Ultra-Massive Galaxy in a Protocluster at z ~ 4.9″ . The author list has a strong University of California flavour: Stephanie M. Urbano Stawinski (UC Irvine), M. C. Cooper (UC Irvine), Ben Forrest (UC Davis) , Adam Muzzin (York University, Canada), Danilo Marchesini (Tufts University), Gillian Wilson (UC Merced), Percy Gomez (Keck Observatories, USA), Ian McConachie (UC Riverside), Z. Cemile Marsan (York University, Canada), Marianna Annuziatella (Centro de Astrobiología CSIC-INTA, Spain) and Wenjun Chang (UC Riverside).
This paper presents an investigation of a cluster system involving a massive galaxy using Keck spectroscopy with determination of its redshift and star formation properties. The results pose a challenge for theorists. The paper is in the folder marked Astrophysics of Galaxies.
Here is a screen grab of the overlay which includes the abstract:
You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.
The second paper, also published on Friday 14th June and has the title “Boil-off of red supergiants: mass loss and type II-P supernovae” by Jim Fuller (Caltech) and Daichi Tsuna (Caltech, USA and University of Tokyo, Japan). This one, which is in the folder marked Solar and Stellar Astrophysics, discusses A new model for stellar mass loss which predicts that low-mass red supergiants lose less mass than commonly assumed, while high-mass red supergiants lose more.
Here is a screen grab of the overlay which includes the abstract:
You can click on the image of the overlay to make it larger should you wish to do so. You can find the officially accepted version of the paper on the arXiv here.
That concludes this week’s update. Will we reach 50 for 20204 next week? Tune in next Saturday to find out!
https://telescoper.blog/2024/06/15/two-new-publications-at-the-open-journal-of-astrophysics-11/
#arXiv240416036v3Search_ #arXiv240521049v2 #AstrophysicsOfGalaxies #galaxyClusters #KeckTelescopes #massLoss #protocluster #redSupergiants #redshift #SolarAndStellarAstrophysics #spectroscopy #stellarMassLoss #supernovae #TheOpenJournalOfAstrophysics
#SPT2349-56: The Most #Massive and Active #protocluster Known at z=4.3
https://ui.adsabs.harvard.edu/abs/2017gcf..confE...1D/abstract
As part of the follow-up of bright 1.4mm sources from the South Pole Telescope 2500 square degree survey, we have identified a unique proto-cluster at z=4.3. Using ALMA CO(4-3) and [CII] spectroscopy, we have spectroscopically confirmed at least 12 members within a radius of 13 arcseconds. These 12 members have a combined star formation rate of 6800 M_sol/yr, which may increase up to 22000 M_sol/yr if the entire LABOCA 870µm flux of 100 mJy is accounted for. The 12 members have a velocity dispersion of 500 km/s, implying a virial mass of 2x10<SUP>13</SUP> M_sol. This makes SPT2349-56 a truly unique proto-cluster both in terms of mass and star-formation rate.
Referenced link: https://phys.org/news/2023-03-astronomers-gas-cloud-galactic-protocluster.html
Discuss on https://discu.eu/q/https://phys.org/news/2023-03-astronomers-gas-cloud-galactic-protocluster.html
Originally posted by Phys.org / @physorg_com: http://nitter.platypush.tech/physorg_com/status/1636007358760472577#m
Astronomers observe scorching gas cloud surrounding a galactic #protocluster @AAS_Office https://hcvalidate.perfdrive.com/fb803c746e9148689b3984a31fccd902// https://phys.org/news/2023-03-astronomers-gas-cloud-galactic-protocluster.html
https://arxiv.org/abs/2211.09097
A spectroscopically confirmed protocluster 650 million years after the Big Bang, located behind Abell 2744 (Pandora's Cluster)
The highest redshift spectroscopically confirmed protocluster to date, demonstrating the power of #JWST to probe the universe at very early times.
#protocluster #galaxy #cluster #pandoracluster #jwst #webb #nasawebb #esawebb #unfoldtheuniverse #universe #cosmology #astronomy #astrophysics #space #deepsky #astroph #science #cosmos #astrodon
We present the spectroscopic confirmation of a protocluster at $z=7.88$ behind the galaxy cluster Abell2744 (hereafter A2744-z7p9OD). Using JWST NIRSpec, we find seven galaxies within a projected radius of 60kpc. Although the galaxies reside in an overdensity around $>20\times$ greater than a random volume, they do not show strong Lyman-alpha emission. We place 2-$σ$ upper limits on the rest-frame equivalent width $<16$-$28$AA. Based on the tight upper limits to the Lyman-alpha emission, we constrain the volume-averaged neutral fraction of hydrogen in the intergalactic medium to be $x_{\rm HI} > 0.45$ (68% CI). Using an empirical $M_{\rm UV}$-$M_{\rm halo}$ relation for individual galaxies, we estimate that the total halo mass of the system is $\gtrsim 4\times10^{11}\,M_\odot$. Likewise, the line of sight velocity dispersion is estimated to be $1100 \pm 200$km/s. Using an empirical relation, we estimate the present-day halo mass of A2744-z7p9OD to be $\sim2\times10^{15}\,M_\odot$, comparable to the Coma cluster. A2744-z7p9OD is the highest redshift spectroscopically confirmed protocluster to date, demonstrating the power of JWST to investigate the connection between dark-matter halo assembly and galaxy formation at very early times with medium-deep observations at $<20$hrs total exposure time. Follow-up spectroscopy of the remaining photometric candidates of the overdensity will further refine the features of this system and help characterize the role of such overdensities in cosmic reionization.
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