Results 51 to 60 of about 64,703 (265)

The Way We Measure: Comparison of Methods to Derive Radial Surface Brightness Profiles [PDF]

, 2016
The breaks and truncations in the luminosity profile of face-on spiral galaxies offer valuable insights in their formation history. The traditional method of deriving the surface photometry profile for face-on galaxies is to use elliptical averaging.
de Jong, R. S., Peters, S. P. C., van der Kruit, P. C.   +2 more
core   +2 more sources

PERICLES: A Set of Empirical Rotational Isochrones Modeled on Cool Dwarfs in Open Clusters and Wide Binaries

Astronomische Nachrichten, Volume 347, Issue 1, January 2026.
ABSTRACT Isochrones, equal‐age curves, are widely used in astrophysics to estimate stellar ages. Classical stellar parameters are, however, very limited in their usability for main sequence stars because of their weak age‐dependence. Here, rotation period measurements provide complementary information.
David Gruner, Sydney A. Barnes
wiley   +1 more source

Accuracy of photometric redshifts for future weak lensing surveys from space

, 2012
Photometric redshifts are a key tool to extract as much information as possible from planned cosmic shear experiments. In this work we aim to test the performances that can be achieved with observations in the near-infrared from space and in the optical ...
Abdalla, Abdalla, Beckwith, Benitez, Bertin, Bolzonella, Bordoloi, Capak, Coe, Collister, Dahlen, Els, Erben, F. Bellagamba, Feldmann, Hildebrandt, Kaiser, Kitching, Kuijken, L. Moscardini, M. Bolzonella, M. Meneghetti, Magnier, Mei, Melchior, Menanteau, Meneghetti, Meneghetti, Rafelski, Rowan-Robinson, Schock, Tokovinin, Umetsu, Way   +33 more
core   +1 more source

Climate Emergency and Different Ways to Fail? The Fermi Paradox, the Simulation Hypothesis, Agency and Hope

Journal for the Theory of Social Behaviour, Volume 55, Issue 4, December 2025.
ABSTRACT Humanity seems stuck on different ways to fail to meet the challenge posed by a declared climate emergency and manifest problems of ecological breakdown. Rather than reprise these failures, we use the Fermi Paradox and simulation hypothesis to make a simple point about agency. The argument unfolds in two sections.
Jamie Morgan
wiley   +1 more source

The Baryonic Tully–Fisher Relation. II. Stellar Mass Models

The Astronomical Journal
We present new color–ϒ _* (mass-to-light ratio) models to convert Wide-field Infrared Survey Explorer W1 fluxes into stellar masses. We outline a range of possible star formation histories and chemical evolution scenarios to explore the confidence limits
Francis Duey, James Schombert, Stacy McGaugh, Federico Lelli   +3 more
doaj   +1 more source

Reconstructing Galaxy Spectral Energy Distributions from Broadband Photometry [PDF]

, 1999
We present a novel approach to photometric redshifts, one that merges the advantages of both the template fitting and empirical fitting algorithms, without any of their disadvantages.
A. J. Connolly, A. S. Szalay, I. Csabai, Karhunen H., Madau P., T. Budavári   +5 more
core   +2 more sources

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

The void galaxy survey: photometry, structure and identity of void galaxies [PDF]

Monthly Notices of the Royal Astronomical Society, 2016
We analyze photometry from deep B-band images of 59 void galaxies in the Void Galaxy Survey (VGS), together with their near-infrared 3.6$μ$m and 4.5$μ$m Spitzer photometry. The VGS galaxies constitute a sample of void galaxies that were selected by a geometric-topological procedure from the SDSS DR7 data release, and which populate the deep interior of
B. Beygu, R. F. Peletier, J. M. van der Hulst, T. H Jarrett, K. Kreckel, R. van de Weygaert, J. H. van Gorkom, M. A. Aragon-Calvo   +7 more
openaire   +4 more sources

HEAD IN THE STARS, FEET ON THE GROUND: Scale and Astronomy Initiatives in Southern Africa

Cultural Anthropology, Volume 40, Issue 4, Page 571-596, November 2025.
ABSTRACT This article explores the evolution of radio astronomy in South Africa and Madagascar, focusing on how “scale” functions as both a way of understanding the world and marking differences in existence. In outer space research, the ground is crucial but often overlooked.
HANNA NIEBER, DAVIDE CHINIGÒ
wiley   +1 more source

JWST Photometry of Globular Cluster Populations in MACS0417.5−1154

The Astrophysical Journal
Deep JWST imaging of the massive galaxy cluster MACS0417.5−1154, at redshift z = 0.443, reveals a huge population of globular clusters (GCs) and ultracompact dwarfs (UCDs) primarily distributed around its single central giant brightest cluster galaxy ...
William E. Harris, Marta Reina-Campos, Kaitlyn E. Keatley, Maruša Bradač, Nicholas S. Martis, Adam Muzzin, Gaël Noirot, Ghassan T. E. Sarrouh, Marcin Sawicki, Chris J. Willott, Samantha C. Berek   +10 more
doaj   +1 more source