Results 71 to 80 of about 1,069,925 (330)

The abundance of dark galaxies [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2002
We show that gas in a large fraction of low mass dark matter halos may form Toomre stable disks, if angular momentum is conserved when the gas contracts. Such halos would be stable to star formation and therefore remain dark. This may potentially explain the discrepancy between the predicted and observed number of dwarf satellites in the Local Group ...
Verde, Licia, Oh, S. Peng, Jimenez, Raul
openaire   +2 more sources

The THESEUS Space Mission and the Infrared Telescope Calibration Unit

open access: yesAstronomische Nachrichten, EarlyView.
ABSTRACT The Transient High‐Energy Sky and Early Universe Surveyor (THESEUS) is an ESA M7 mission concept currently in Phase A, designed to exploit gamma‐ray bursts to probe the early Universe while advancing multi‐messenger and time‐domain astrophysics. To achieve its ambitious goals, THESEUS will combine wide‐band x‐ray and gamma‐ray monitors with an
András Péter Joó   +9 more
wiley   +1 more source

Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11

open access: yesThe Astrophysical Journal Letters
We interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 ( z = 10.6) using our state-of-the-art chemical evolution models.
Chiaki Kobayashi, Andrea Ferrara
doaj   +1 more source

Chemical Abundances of Planetary Nebulae in M33

open access: yes, 2004
Using spectroscopic data presented in Magrini et al. (2003), we have analyzed with the photoionization code CLOUDY 94.00 (Ferland et al. 1998) 11 Planetary Nebulae belonging to the spiral galaxy M 33. Central star temperatures and nebular parameters have
A. Mampaso   +33 more
core   +1 more source

Sulphur in the Sculptor dwarf spheroidal galaxy - Including NLTE corrections [PDF]

open access: yes, 2015
In Galactic halo stars, sulphur has been shown to behave like other $\alpha$-elements, but until now, no comprehensive studies have been done on this element in stars of other galaxies.
Andrievsky, Sergei M.   +6 more
core   +4 more sources

Reconciling the local galaxy population with damped Lyman α cross-sections and metal abundances [PDF]

open access: yes, 2005
A comprehensive analysis of 355 high-quality Westerbork Synthesis Radio Telescope (WSRT) HI 21-cm line maps of nearby galaxies shows that the properties and incident rate of damped Lyman alpha absorption systems (DLAs) observed in the spectra of high ...
M. Zwaan   +4 more
semanticscholar   +1 more source

The galaxy clustering crisis in abundance matching [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2018
Abstract Galaxy clustering on small scales is significantly underpredicted by sub-halo abundance matching (SHAM) models that populate (sub-)haloes with galaxies based on peak halo mass, Mpeak. SHAM models based on the peak maximum circular velocity, Vpeak, have had much better success.
Duncan Campbell   +7 more
openaire   +2 more sources

Understanding Degradation Mechanisms in Water‐In‐Salt Electrolyte. Part 2: Impact of the Electrochemical Parameters on the Cycling Behavior of LiFePO4 versus TiS2

open access: yesBatteries &Supercaps, EarlyView.
Cycling water‐in‐salt batteries involves complex degradation processes that require multiprobe analysis. Using online electrochemical mass spectrometry (OEMS), postmortem X‐ray photoemission spectroscopy (XPS) (including hard‐XPS), and scanning electron microscopy (SEM), the degradation mechanisms are examined in composite electrodes (TiS2 and LiFePO4)
Célia Doublet   +7 more
wiley   +1 more source

Relationship between the Elemental Abundances and the Kinematics of Galactic-Field RR Lyrae Stars

open access: yes, 2017
Data of our compiled catalog containing the positions, velocities, and metallicities of 415 RR~Lyrae variable stars and the relative abundances [el/Fe] of 12~elements for 101 RR~Lyrae stars, including four $\alpha$~elements (Mg, Ca, Si, and Ti), are used
Gozha, M. L.   +2 more
core   +1 more source

Abundances of Cu and Zn in metal-poor stars: Clues for Galaxy evolution [PDF]

open access: yes, 2002
We present new observations of copper and zinc abundances in 90 metal-poor stars, belonging to the metallicity range −3 100). The trend of Cu and Zn abundances as a function of the metallicity (Fe/H) is discussed and compared to that of other heavy ...
T. Mishenina   +4 more
semanticscholar   +1 more source

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