Results 151 to 160 of about 527,839 (302)

Catalog of Visually Classified Galaxies in the Local ($z\sim0.01$) Universe [PDF]

, 2015
The morphological types of 5840 galaxies were classified by a visual inspection of color images using the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) to produce a morphology catalog of a representative sample of local galaxies with $z<0.01$. The sample galaxies are almost complete for galaxies brighter than $r_{pet}=17.77$.
arxiv   +1 more source

Beyond Accretion Limits: The Rise of Pulsating Gems

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The discovery of several ultraluminous X‐ray sources exhibiting fast and rapidly evolving X‐ray pulsations unequivocally associates these sources with accreting neutron stars orbiting relatively massive companion stars (> 8M ⊙$$ {}_{\odot } $$).
Gian Luca Israel, Roberta Amato, Matteo Imbrogno, Nicoló Oreste Pinciroli Vago, on behalf of a Larger Team, Guillermo Andres Rodríguez Castillo, Andrea Belfiore, Luigi Stella, Matteo Bachetti, Felix Fürst, Dom Walton, Matthew Middleton, Murray Brightman, Fabio Pintore, Ciro Pinto, Silvia Conforti, Luca Zampieri, Chiara Salvaggio, Anna Wolter, Andrea Tiengo, Andrea De Luca, Paolo Esposito, Ruben Salvaterra, Hannah Earnshaw, Tim Roberts, Andres Gúrpide, Sara Motta   +26 more
wiley   +1 more source

Strong He i Emission Lines in High N/O Galaxies at z ∼ 6 Identified in JWST Spectra: High He/H Abundance Ratios or High Electron Densities?

The Astrophysical Journal
We present He i /H β flux and He/H abundance ratios in three James Webb Space Telescope galaxies with significant constraints on N/O abundance ratios, GS-NDG-9422, RXCJ2248-ID, and GLASS150008 at z ∼ 6 mostly with the spectroscopic coverage from He i λ ...
Hiroto Yanagisawa, Masami Ouchi, Kuria Watanabe, Akinori Matsumoto, Kimihiko Nakajima, Hidenobu Yajima, Kentaro Nagamine, Koh Takahashi, Minami Nakane, Nozomu Tominaga, Hiroya Umeda, Hajime Fukushima, Yuichi Harikane, Yuki Isobe, Yoshiaki Ono, Yi Xu, Yechi Zhang   +16 more
doaj   +1 more source

Mass growth of massive quiescent galaxies in the Illustris TNG simulation

Acta Polytechnica
Interactions between galaxies could potentially lead to increased rates of star formation within these galaxies, potentially leading to the occurrence of multiple core-collapse supernovae and the ejection of hot gas.
Bendegúz Koncz, András Péter Joó
doaj   +1 more source

THE LOCAL DWARF GALAXIES:BUILDING BLOCKS OFMASSIVE ONES? I.THE FORNAX DWARF GALAXY

Odessa Astronomical Publications, 2008
A chemical evolution of the Local Group dwarf galaxy Fornax is considered in the framework of the merger scenario. We suppose a galactic stellar halo to be formed as separate fragments which then merge; thus, we can calculate the set of such the ...
T. V. Nykytyuk
doaj   +1 more source

Star Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of "Transition" Galaxies

, 2002
We present new H-alpha narrow band imaging of the HII regions in eight Sculptor Group dwarf irregular (dI) galaxies. Comparing the Sculptor Group dIs to the Local Group dIs, we find that the Sculptor Group dIs have, on average, lower values of SFR when ...
Babul A., Binggeli B., Bomans D. J., Brosch N., Bryan W. Miller, Efstathiou G., Evan D. Skillman, Heisler C. A., Quinn T., Scalo J. M., Stéphanie Côté   +10 more
core   +1 more source

Forged in FIRE: cusps, cores and baryons in low-mass dwarf galaxies [PDF]

, 2015
We present multiple ultrahigh resolution cosmological hydrodynamic simulations of M_★ ≃ 10^(4–6.3) M_⊙ dwarf galaxies that form within two M_(vir) = 10^(9.5–10) M_⊙ dark matter halo initial conditions.
J. Oñorbe, M. Boylan-Kolchin, J. Bullock, P. Hopkins, Duvsan Kerves, C. Faucher-Giguére, E. Quataert, N. Murray   +7 more
semanticscholar   +1 more source

Highly Significant Detection of X‐Ray Polarization in Sco X‐1 and Its Polarization Angle Misaligned With the Direction of the Radio Jet

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The Imaging X‐ray Polarimetry Explorer has successfully measured the X‐ray polarization of Scorpius X‐1, the brightest Z‐source, in the 2–8 keV energy band. The degree of polarization was found to be ∼1.0%$$ \sim 1.0\% $$ with a polarization angle of ∼8$$ \sim 8 $$°. This measurement was conducted simultaneously with NICER, NuSTAR, and Insight‐
Fabio La Monaca, on behalf of IXPE Science Team   +1 more
wiley   +1 more source

Tidal stripping and the structure of dwarf galaxies in the Local Group [PDF]

, 2017
The shallow faint-end slope of the galaxy mass function is usually reproduced in Λ cold dark matter (ΛCDM) galaxy formation models by assuming that the fraction of baryons that turn into stars drops steeply with decreasing halo mass and essentially ...
Azadeh Fattahi, J. Navarro, C. Frenk, K. Oman, Till Sawala, M. Schaller   +5 more
semanticscholar   +1 more source

INTEGRAL Observations of Magnetars

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT The INTEGRAL satellite has collected a large amount of data on magnetars in our Galaxy, spanning more than 20 years starting from 2003. The large data set obtained with the IBIS/ISGRI instrument at energies above 20 keV allows us to study both the properties and long‐term evolution of their persistent hard X‐ray emission and the population ...
Dominik Patryk Pacholski, Lorenzo Ducci, Martin Topinka, Sandro Mereghetti   +3 more
wiley   +1 more source