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We show how the observed hydrogen Balmer and Lyman emission lines constrain the modeling of quiescent solar prominences. We compare space observations of Lyman lines with ground-based observations of Balmer lines for quiescent solar…

Solar and Stellar Astrophysics · Physics 2012-10-03 G. Stellmacher , E. Wiehr

The recent detection of a 3.5 keV X-ray line from the centres of galaxies and clusters by Bulbul et al. (2014a) and Boyarsky et al. (2014a) has been interpreted as emission from the decay of 7 keV sterile neutrinos which could make up the…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Sownak Bose , Wojciech A. Hellwing , Carlos S. Frenk , Adrian Jenkins , Mark R. Lovell , John C. Helly , Baojiu Li

We use N-body simulations to investigate the structure of dark halos in the standard Cold Dark Matter cosmogony. Halos are excised from simulations of cosmologically representative regions and are resimulated individually at high…

Astrophysics · Physics 2008-11-26 Julio F. Navarro , Carlos S. Frenk , Simon D. M. White

[This is truncated to suit the whims of the archivers ...] Parameter studies in LVG models are used to show how the low-lying rotational transitions of common polar molecules HCO+, HCN and CS vary with number density, column density and…

Astrophysics of Galaxies · Physics 2015-06-03 H. S. Liszt

It has been shown that temperatures near the horizon of rotating black holes can be about the phase transition temperature in the Standard Model with the Higgs boson. The distance from the horizon and gravitational and electromagnetic…

General Relativity and Quantum Cosmology · Physics 2022-11-22 A. A. Grib , Yu. V. Pavlov

In the absence of H_2 molecules, the primordial gas in early dark matter halos with virial temperatures just above T_vir >~ 10^4 K cools by collisional excitation of atomic H. Although it cools efficiently, this gas remains relatively hot,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Cien Shang , Greg Bryan , Zoltan Haiman

We report on the detection of deuterated molecular hydrogen, HD, at $z = 0.18$. HD and H$_{\rm 2}$ are detected in HST/COS data of a low metallicity ($Z \sim 0.07Z_\odot$) damped Ly$\alpha$ system at $z = 0.18562$ toward QSO B0120$-$28,…

Astrophysics of Galaxies · Physics 2015-06-18 Cristina M. Oliveira , Kenneth R. Sembach , Jason Tumlinson , John O'Meara , Christopher Thom

Dark matter (DM) can give observable effects decaying or annihilating with production of electrons or/and photons. Such probability was widely researched for our Galaxy. Here we consider one aspect of similar effect for Andromeda galaxy. We…

High Energy Astrophysical Phenomena · Physics 2020-11-11 K. M. Belotsky , E. S. Shlepkina , M. L. Soloviev

We present a model for the interpretation of the gamma-ray background emission from the Galactic halo, which we attribute to interaction of high-energy cosmic rays with dense molecular clumps. In a wide range of clump parameters we…

Astrophysics · Physics 2007-05-23 P. M. W. Kalberla , Yu. A. Shchekinov , R. -J. Dettmar

The feasibility of making highly redshifted HI 21-cm (rest frame) measurements from an early epoch of the Universe between the Dark Ages and Reionization (i.e., z>6 and nu<200 MHz) to probe the effects of feedback from the first stars and…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-15 Jack O. Burns

Near 20.48K and in the temperature range 60--70K, anomalous behavior of thermodynamic, spectral, plastic, elastic and other properties of solid methane is observed. The anomalies in the vicinity of 20.48K are due to the phase $\alpha-\beta$…

Materials Science · Physics 2017-09-12 A. V. Leont'eva , A. Yu. Zakharov , A. Yu. Prokhorov

We study the prospects for observing H$_2$ and HD emission during the assembly of primordial molecular cloud cores. The primordial molecular cloud cores, which resemble those at the present epoch, can emerge around $1+z \sim 20$ according…

Astrophysics · Physics 2009-11-07 H. Kamaya , J. Silk

A study of the line shapes of hydrogen Balmer series lines in RF generated low pressure H2/He plasmas produced results suggesting a catalytic process between helium and hydrogen species results in the generation of 'hot' (ca. 28 eV) atomic…

Plasma Physics · Physics 2007-05-23 Jonathan Phillips , Chun-Ku Chen , Toshi Shiina

We performed Herschel/HIFI observations of intermediate-excitation molecular lines in the far-infrared/submillimeter range in a sample of ten protoplanetary nebulae and young planetary nebulae. The high spectral resolution provided by HIFI…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. Bujarrabal , J. Alcolea , R. Soria-Ruiz , the HIFISTARS team

Photoheating of the gas in low-mass dark matter (DM) haloes prevents baryons from cooling, leaving the haloes free of stars. Gas in these 'dark' haloes remains exposed to the ultraviolet background (UVB), and so is expected to emit via…

Astrophysics of Galaxies · Physics 2019-05-09 Calvin Sykes , Michele Fumagalli , Ryan Cooke , Tom Theuns , Alejandro Benitez-Llambay

We consider indirect detection signals of atomic dark matter, with a massive dark photon which mixes kinetically with hypercharge. In significant regions of parameter space, dark matter remains at least partially ionized today, and dark…

High Energy Physics - Phenomenology · Physics 2015-04-29 Lauren Pearce , Kalliopi Petraki , Alexander Kusenko

Dark matter (DM) particles in the Universe accumulate in neutron stars (NSs) through their interactions with ordinary matter. It has been known that their annihilation inside the NS core causes late-time heating, with which the surface…

High Energy Physics - Phenomenology · Physics 2019-07-05 Koichi Hamaguchi , Natsumi Nagata , Keisuke Yanagi

We analyze the possibilities of detecting a signal in the hydrogen 21~cm line, which was formed in the early Universe during the the Dark Ages cosmological epoch, using the Ukrainian radio telescopes UTR-2 and GURT of the National Academy…

A new molecular hydrogen cloud has been identified at z = 3.025 in the absorption-line spectrum of the quasar 0347-3819 observed with the UVES spectrograph at the VLT/Kueyen telescope. At the same redshift numerous metal lines and the DI…

Astrophysics · Physics 2007-05-23 S. A. Levshakov , P. Molaro , M. Dessauges-Zavadsky , S. D'Odorico

We use numerical simulations of critically-closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to $256^3$ particles using the particle-mesh (PM) method and…

Astrophysics · Physics 2009-10-22 James M. Gelb , Edmund Bertschinger
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