Results 81 to 90 of about 425,135 (224)

Dark Matter in Spiral Galaxies [PDF]

Symposium - International Astronomical Union, 1995
In this review I will concentrate on three questions concerning the issue of dark matter in spiral galaxies. In the first place (and for the most part) I will discuss the analysis of rotation curves and the question whether the “maximum–disk hypothesis” is valid.
openaire   +2 more sources

Towards an Algorithmic Guide to Spiral Galaxies [PDF]

Theoretical Computer Science, 2014
In this paper, we are interested in the one-player game Spiral Galaxies, and study it from an algorithmic viewpoint. Spiral Galaxies has been shown to be NP-hard [Friedman, 2002] more than a decade ago, but so far it seems that no one has dared exploring its algorithmic universe. We take this trip and visit some of its corners.
Guillaume Fertin, Shahrad Jamshidi, Christian Komusiewicz   +2 more
openaire   +4 more sources

Exploring the star formation histories of galaxies [PDF]

, 1999
In this thesis, I explore the star formation histories of both spiral and elliptical galaxies. In Part 1,1 present an in-depth study of the star formation histories of spiral galaxies with a wide range of properties. Optical and near-infrared colours are
Bell, Eric Findlay, Bell, E.F.
core  

Early assembly of the most massive galaxies [PDF]

, 2009
The current consensus is that galaxies begin as small density fluctuations in the early Universe and grow by in situ star formation and hierarchical merging(1).
Chris A. Collins, Scott T Kay (16045382), Nicola Mehrtens (16047884), Ed Lloyd-Davies, Hoyle, Ben, Hosmer, Mark, Christopher J. Miller, Ben Hoyle, Mehrtens, Nicola, Robert G. Mann, Pedro T. P. Viana, Martin Sahlén (267044), S Adam Stanford (16061237), Mark Hosmer (16070585), Robert C Nichol (16067396), John P Stott (16070582), Martin Sahlén, Sahlen, Martin, John P. Stott, Kathy Romer (4460893), Matt Hilton (6956609), Viana, Pedro T. P., Mann, Robert G., Ben Hoyle (6914513), Stott, John P., Matt Hilton, Robert G Mann (7965452), Andrew Liddle, Stanford, S. Adam, Christopher J Miller (16070591), A. Kathy Romer, Davidson, Michael, Ed Lloyd-Davies (16075100), Romer, A. Kathy, Robert C. Nichol, Andrew Liddle (16042793), Pedro T P Viana (16045379), Nichol, Robert C., Kay, Scott T., Michael J. West, Chris A Collins (16061234), Scott T. Kay, Collins, Chris A., Michael Davidson, Mark Hosmer, West, Michael J., Michael Davidson (699678), S. Adam Stanford, Michael J West (5524436), Liddle, Andrew, Nicola Mehrtens, Miller, Christopher J., Hilton, Matt, Lloyd-Davies, Ed   +53 more
core   +1 more source

Extragalactic Magnetism with SOFIA (SALSA Legacy Program). V. First Results on the Magnetic Field Orientation of Galaxies

The Astrophysical Journal, 2023
We present the analysis of the magnetic field ( B -field) structure of galaxies measured with far-infrared (FIR) and radio (3 and 6 cm) polarimetric observations.
Alejandro S. Borlaff, Enrique Lopez-Rodriguez, Rainer Beck, Susan E. Clark, Evangelia Ntormousi, Konstantinos Tassis, Sergio Martin-Alvarez, Mehrnoosh Tahani, Daniel A. Dale, Ignacio del Moral-Castro, Julia Roman-Duval, Pamela M. Marcum, John E. Beckman, Kandaswamy Subramanian, Sarah Eftekharzadeh, Leslie Proudfit   +15 more
doaj   +1 more source

Genomic Insights Into the Multimetal Resilience and Biofilm‐Templated Nanorod Biosynthesis of Stenotrophomonas bentonitica BII‐R7: Bioremediation and Green Nanotechnology Implications

Microbial Biotechnology, Volume 19, Issue 9, September 2026.
Biofilm extracellular polymeric substances (EPS) in Stenotrophomonas bentonitica BII‐R7 direct the formation of crystalline trigonal selenium nanorods. Comparative genomics identifies a unique genetic toolkit underpinning EPS composition and metal resilience, positioning this strain as a platform for bioremediation and green nanomaterial synthesis ...
Eduardo Perez‐Muelas, Miguel Angel Ruiz‐Fresneda, Guillermo Lazuen‐Lopez, Tatiana Lopez‐Perez, Fouad Eddaoudi‐Lakraichi, Mohammed Bakkali, Mohamed Larbi Merroun   +6 more
wiley   +1 more source

A simple model of spiral galaxies from geometric optics

AIP Advances
We propose a simple model of spiral galaxies based on the interference of gravitational waves. The interference is deduced from geometric optics analysis of the refractive index profiles that mimic the behavior of gravitational potentials −1/r and r2. We
Bogdan Szafraniec, James N. Blake
doaj   +1 more source

Dwarfs from the Dark (Energy Survey): a machine learning approach to classify dwarf galaxies from multi-band images

The Open Journal of Astrophysics, 2021
Countless low-surface brightness objects - including spiral galaxies, dwarf galaxies, and noise patterns - have been detected in recent large surveys.
Oliver Müller, Eva Schnider
doaj   +1 more source

The 40K‐K dating system: 1. Improving data interpretation using new model calculations

Meteoritics &Planetary Science, Volume 61, Issue 9, Page 2187-2200, September 2026.
Abstract The 40K‐K cosmic‐ray exposure (CRE) dating system offers a promising method for determining exposure ages of iron meteorites by combining the radioactive cosmogenic 40K with the stable cosmogenic isotopes 39K and 41K. However, earlier applications relied on semi‐empirical production models and inconsistent analytical data sets, limiting their ...
Farshid Nozarian, Suzette Timmerman, Ingo Leya   +2 more
wiley   +1 more source

FORMATION AND MAINTENANCE OF SPIRAL STRUCTURE IN GALAXIES [PDF]

Symposium - International Astronomical Union, 1985
The formation and maintenance of spiral structure in galaxies is discussed in terms of spiral modes with a general perception consistent with the hypothesis of quasi-stationary spiral structure. The latter is explained in some detail to give it the original proper perspective and to contrast it with recent studies of non-stationary spiral structures ...
C. C. Lin, G. Bertin
openaire   +1 more source