Results 61 to 70 of about 48,997 (217)

Ultra-low-frequency Gravitational Waves from Massive Clusters at z ∼ 1

The Astrophysical Journal, 2023
Recent progress with pulsar timing array experiments, especially from the NANOGrav collaboration, indicates that we are on the cusp of detecting significant signals from the inspiral of supermassive black hole (BH) binaries.
David K. Wendt, Roger W. Romani
doaj   +1 more source

A GMBCG Galaxy Cluster Catalog of 55,424 Rich Clusters from SDSS DR7

, 2010
We present a large catalog of optically selected galaxy clusters from the application of a new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data.
Abazajian, Abell, Adami, Annis, August Evrard, Barger, Barrientos, Bartelmann, Benjamin P. Koester, Berlind, Bernstein, Blakeslee, Blakeslee, Blanton, Bower, Burenin, Böhringer, Couch, David E. Johnston, David Gerdes, Dong, Eduardo Rozo, Efstathiou, Eisenhardt, Eisenstein, Eli S. Rykoff, Erin Sheldon, Gal, Gal, Gal, Gerdes, Gladders, Gladders, Gladders, Gladders, Gladders, Goto, Hansen, Hao, Hao, Hao, Hao, James Annis, Jiangang Hao, Johnston, Kepner, Kim, Koester, Koester, Li, Lopes, López-Cruz, Majumdar, Matthew Becker, Mei, Michael Busha, Miller, Mullis, Navarro, Oukbir, Oyaizu, Papovich, Perlmutter, Postman, Ramella, Riess, Risa H. Wechsler, Rozo, Rozo, Rozo, Rozo, Rykoff, Seth R. Siegel, Sheldon, Silverman, Spergel, Spergel, The Dark Energy Survey Collaboration., Timothy A. McKay, Wen, Yang, York   +81 more
core   +2 more sources

Redshift‐Agnostic Machine Learning Classification: Unveiling Peak Performance in Galaxy, Star, and Quasar Classification (Using SDSS DR17)

Astronomische Nachrichten, Volume 346, Issue 5, June 2025.
ABSTRACT Classification of galaxies, stars, and quasars using spectral data is fundamental to astronomy, but often relies heavily on redshift. This study evaluates the performance of 10 machine learning algorithms on SDSS data to classify these objects, with a particular focus on scenarios where redshift information is unavailable.
Debashis Chatterjee, Prithwish Ghosh
wiley   +1 more source

Spectroscopic Confirmation of a Massive Protocluster with Two Substructures at z ≃ 3.1

The Astrophysical Journal
We present the results of a Keck and Northern Extended Millimeter Array spectroscopic survey of 507 galaxies, where we confirm the presence of two massive overdensities at z = 3.090−3.110 and z = 3.133−3.155 in the neighborhood of the GOODS-N, each with ...
Michael J. Nicandro Rosenthal, Amy J. Barger, Lennox L. Cowie, Logan H. Jones, Stephen J. McKay, Anthony J. Taylor   +5 more
doaj   +1 more source

Galaxy colours in high-redshift, X-ray-selected clusters - I. Blue galaxy fractions in eight clusters [PDF]

Monthly Notices of the Royal Astronomical Society, 2002
We present initial results from a wide-field, multi-colour imaging project, designed to study galaxy evolution in X-ray selected clusters at intermediate (z~0.25) and high redshifts (z~0.5). In this paper we give blue galaxy fractions from eight X-ray selected clusters, drawn from a combined sample of three X-ray surveys.
Fairley, B. W., Jones, L. R., Wake, D. A., Collins, C. A., Burke, D. J., Nichol, R. C., Romer, A. K.   +6 more
openaire   +4 more sources

Lactea: Web‐Based Spectrum‐Preserving Multi‐Resolution Visualization of the GAIA Star Catalog

Computer Graphics Forum, Volume 44, Issue 3, June 2025.
Abstract The explosion of data in astronomy has resulted in an era of unprecedented opportunities for discovery. The GAIA mission's catalog, containing a large number of light sources (mostly stars) with several parameters such as sky position and proper motion, is playing a significant role in advancing astronomy research and has been crucial in ...
Reem Alghamdi, Markus Hadwiger, Guido Reina, Alberto Jaspe‐Villanueva   +3 more
wiley   +1 more source

The NIKA2 Sunyaev-Zeldovich Large Program [PDF]

EPJ Web of Conferences
The NIKA2 camera operating at the IRAM 30-m telescope excels in high-angular resolution mapping of the thermal Sunyaev-Zel’dovich effect towards galaxy clusters at intermediate and high-redshift. As part of the NIKA2 guaranteed-time, the SZ Large Program
Perotto L., Adam R., Ade P., Ajeddig H., André P., Artis E., Aussel H., Barrena R., Bartalucci I., Beelen A., Benoît A., Berta S., Bing L., Bourrion O., Calvo M., Catalano A., De Petris M., Désert F.-X., Doyle S., Driessen E. F. C., Ejlali G., Ferragamo A., Gomez A., Goupy J., Hanser C., Katsioli S., Kéruzoré F., Kramer C., Ladjelate B., Lagache G., Leclercq S., Lestrade J.-F., Macías-Pérez J.F., Madden S. C., Maury A., Mauskopf P., Mayet F., Monfardini A., Moyer-Anin A., Muñoz-Echeverría M., Paliwal A., Pisano G., Pointecouteau E., Ponthieu N., Pratt G.W., Revéret V., Rigby A. J., Ritacco A., Romero C., Roussel H., Ruppin F., Schuster K., Sievers A., Tucker C., Yepes G.   +54 more
doaj   +1 more source

swPHoToNs: Toward trillion‐body‐scale cosmological N‐body simulations on Sunway TaihuLight supercomputer

Engineering Reports, Volume 7, Issue 3, March 2025.
We present the details of implementing a highly efficient and scalable Cosmological N‐body simulation framework on the heterogeneous many‐core supercomputer Sunway TaihuLight. We manage to conduct cosmological simulations which contain up to 1.6 trillion particles, obtaining a sustained performance of 56.3 PFlops with a weak‐scaling parallel efficiency
Zhao Liu, Qiao Wang, Xiaojing Lv, Xu Liu, Hongsong Meng, Guanghui Zhu, Liang Gao, Haohuan Fu, Guangwen Yang   +8 more
wiley   +1 more source

MAGAZ3NE: Evidence for Galactic Conformity in z ≳ 3 Protoclusters

The Astrophysical Journal
We examine the quiescent fractions of massive galaxies in six z ≳ 3 spectroscopically confirmed protoclusters in the COSMOS field, one of which is newly confirmed and presented here. We report the spectroscopic confirmation of MAGAZ3NE J100143+023021 at $
Ian McConachie, Gillian Wilson, Ben Forrest, Z. Cemile Marsan, Adam Muzzin, M. C. Cooper, Marianna Annunziatella, Danilo Marchesini, Percy Gomez, Wenjun Chang, Stephanie M. Urbano Stawinski, Michael McDonald, Tracy Webb, Allison Noble, Brian C. Lemaux, Ekta A. Shah, Priti Staab, Lori M. Lubin, Roy R. Gal   +18 more
doaj   +1 more source

Hierarchical Clustering and the Butcher-Oemler Effect

, 1994
We show that the rapid evolution in the fraction of blue, star-forming galaxies seen in clusters as a function of redshift (the Butcher-Oemler effect) can be explained very simply if structure formation in the universe proceeeds hierarchically.
Kauffmann, Guinevere
core   +2 more sources