Results 91 to 100 of about 471,519 (339)

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

Astronomische Nachrichten, EarlyView.
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

Exploring Dark Photon Production and Kinetic Mixing Constraints in Heavy‐Ion Collisions

Astronomische Nachrichten, EarlyView.
ABSTRACT Vector U‐bosons, often referred to as “dark photons,” are potential candidates for mediating dark matter interactions. In this study, we outline a procedure to derive theoretical constraints on the upper bound of the kinetic mixing parameter ϵ2MU$$ {\upvarepsilon}^2\left({M}_U\right) $$ using dilepton data from heavy‐ion from SIS to RHIC ...
Adrian William Romero Jorge, Elena Bratkovskaya, Taesoo Song, Laura Sagunski   +3 more
wiley   +1 more source

Rotation curves and metallicity gradients from HII regions in spiral galaxies

, 2002
In this paper we study long slit spectra in the region of H$\alpha$ emission line of a sample of 111 spiral galaxies with recognizable and well defined spiral morphology and with a well determined environmental status, ranging from isolation to non ...
Bettoni, D., Galletta, G., Marquez, I., Masegosa, J., Moles, M., Varela, J.   +5 more
core   +1 more source

Galaxy Harassment—Interactions for the 90s [PDF]

Symposium - International Astronomical Union, 1999
The origin of the Hubble sequence remains a long-standing puzzle in astronomy. Giant galaxies range from slowly-rotating dense ellipticals to thin late-type spiral disks. At the faint end, there are two distinct classes of “ellipticals/spheroids” that are easily separated in plots of nearly any two of their properties, such as central surface ...
George Lake, Ben Moore
openaire   +2 more sources

Staphylococcus Aureus AgrA Modulators from South African Antimicrobial Plants.

Chemistry &Biodiversity, Accepted Article.
South African plants are an underutilized metabolites source for novel antimicrobials targeting key quorum sensing (QS) systems like the Staphylococcus aureus AgrA. AgrA modulating metabolites constitute a new approach to reducing resistance development.
Christiana Eleojo Aruwa, Saheed Sabiu
wiley   +1 more source

Pair-Matching of Radio-Loud and Radio-Quiet AGNs

Frontiers in Astronomy and Space Sciences, 2017
Active galactic nuclei (AGNs) are known to cover an extremely broad range of radio luminosities and the spread of their radio-loudness is very large at any value of the Eddington ratio.
Dorota Kozieł-Wierzbowska, Grażyna Stasińska, Natalia Vale Asari, Marek Sikora, Elisa Goettems, Anna Wójtowicz   +5 more
doaj   +1 more source

Modelling ISO Galaxy Counts with Luminosity and Merger Rate Evolution [PDF]

, 1998
We model galaxy evolution in the 6.75 and 15 micron passbands of the ISO satellite, by combining models of galaxy evolution at optical wavelengths (which are consistent with the optical galaxy counts) with observed spectral energy distributions in the ...
Eales, Steve, Roche, Nathan
core   +2 more sources

Evolution of Galaxies Through Their Interactions [PDF]

Symposium - International Astronomical Union, 1996
We investigated how the encounters between galaxies change their mass M and velocity dispersion σ. We carried out a series of direct N-body simulation of encounters of two spherical galaxies. In Figure 1, the relative change of energy ΔE/E are plotted against that of mass ΔM/M for various initial conditions.
J. Marino, Y. Funato
openaire   +2 more sources

Characterization of the Cubamyces menziesii terpenome

ChemBioChem, Accepted Article.
Long‐lasting polypore fungi are significant producers of terpene cyclases of high interest for medicinal or biotechnological applications. Following the 1,000 Fungal Genomes initiative launched by the Joint Genome Institute, we explored the genome of Cubamyces (C.) menziesii and identified eighteen genes encoding sesquiterpene cyclases. In a search for
Gilles Iacazio, Létitia Leydet, Julie Couillaud, Agnès Amouric, Elise Courvoisier-Dezort, Carole Avesque, Thierry Giardina, Mireille Attolini, Pierre Rousselot-Paillet, Katia Duquesne, Marie-Noelle Rosso   +10 more
wiley   +1 more source

ChAInGeS: The Chandra Arp Interacting Galaxies Survey

, 2011
We have conducted a statistical analysis of the ultra-luminous X-ray point sources (ULXs; L(X) >= 10^39 erg/s) in a sample of galaxies selected from the Arp Atlas of Peculiar Galaxies.
Abazajian, Alonso-Herrero, Alonso-Herrero, Arp, Barton, Barton Gillespie, Begelman, Beverly J. Smith, Casosola, Colbert, Curtis Struck, de Vaucouleurs, Donzelli, Douglas A. Swartz, Duc, Duc, Ellison, Evans, Gao, Haan, Hancock, Imanishi, Jacob A. Burleson, Jester, Kennicutt, King, Kuntz, Lehmer, Liu, Liu, Liu, Liu, Lucero, Michael A. Nowak, Mirabel, Modica, Moretti, Moustakas, Moustakas, Mukai, Norris, Olivia Miller, Pakull, Pakull, Parma, Parra, Petric, Ptak, Ptak, Richards, Rothberg, Schlegel, Sekiguchi, Silverman, Smith, Smith, Smith, Smith, Smith, Stoughton, Struck, Surace, Swartz, Swartz, Swartz, Swartz, Tao, Tennant, Terashima, Veilleux, Werk, Xu, Zezas, Zhang, Zombeck   +74 more
core   +1 more source