English
Related papers

Related papers: Molecular hydrogen in the cosmic recombination epo…

200 papers

Here I describe recent studies of objects with molecular hydrogen emission that is strong relative to other spectral lines. Large telescopes and fast spectrometers have made the 2 {\mu}m window accessible even for relatively faint objects.…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-25 Gary J. Ferland

We introduce a sub-grid model for the non-equilibrium abundance of molecular hydrogen in cosmological simulations of galaxy formation. We improve upon previous work by accounting for the unresolved structure of molecular clouds in a…

Astrophysics of Galaxies · Physics 2015-06-19 Matteo Tomassetti , Cristiano Porciani , Emilio Romano-Diaz , Aaron D. Ludlow

Transition of an electron from a free to a bound state is critical in determining the qualitative shape of the spectrum in high-order harmonic generation (HHG), and in tomographic imaging of orbitals. We calculate and compare the…

A key assumption of the standard cosmological model is that the temperature of the cosmic microwave background (CMB) radiation scales with cosmological redshift $z$ as $T_{\rm CMB}(z) \propto (1+z)$ at all times after recombination at…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-10 J. Colin Hill , Boris Bolliet

High harmonic generation (HHG) is used to measure the spectral phase of the recombination dipole matrix element (RDM) in argon over a broad frequency range that includes the 3p Cooper minimum (CM). The measured RDM phase agrees well with…

Atomic Physics · Physics 2015-06-17 S. B. Schoun , R. Chirla , J. Wheeler , C. Roedig , P. Agostini , L. F. DiMauro , K. J. Schafer , M. B. Gaarde

The electronic structure of the hydrogen molecule is investigated for the parallel configuration. The ground states of the Sigma manifold are studied for ungerade and gerade parity as well as singlet and triplet states covering a broad…

Chemical Physics · Physics 2009-10-30 T. Detmer , P. Schmelcher , F. K. Diakonos , L. S. Cederbaum

The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by very strong molecular hydrogen emission lines on a faint IR continuum. The H2 emission originates in the northern component of a double-galaxy system associated…

Astrophysics · Physics 2009-11-13 Patrick Ogle , Robert Antonucci , P. N. Appleton , David Whysong

We present a study of non-sequential double recombination (NSDR) high harmonic generation (HHG) in a molecular-like system. Using a Coulomb-corrected three-step model we are able to classically describe the observed NSDR HHG cutoffs…

Atomic Physics · Physics 2017-07-12 Kenneth K. Hansen , Lars Bojer Madsen

Precise solutions of the Hartree-Fock equations for the ground state of the hydrogen molecule are obtained for a wide range of internuclear distances R by means of a two-dimensional fully numerical mesh computational method. The spatial…

Atomic Physics · Physics 2007-05-23 Mikhail V. Ivanov

We report an upper limit of 9 x 10^{12} cm-2 on the column density of water in the translucent cloud along the line of sight toward HD 154368. This result is based upon a search for the C-X band of water near 1240 \AA carried out using the…

Astrophysics · Physics 2009-10-30 Marco Spaans , David Neufeld , Stephen Lepp , Gary J. Melnick , John Stauffer

Non-sequential double recombination (NSDR) high-order harmonic generation (HHG) is studied in a molecular system. We observe a unique molecular two-electron effect with a characteristic cutoff in the HHG spectrum at higher energies than…

Atomic Physics · Physics 2016-06-08 Kenneth K. Hansen , Lars Bojer Madsen

The cosmic microwave background absorption intensity in the 21 cm line of neutral hydrogen in the presence of additional power in the form of a "bump" in the spectrum of cosmological density perturbations is calculated. The main…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-09 Yu. N. Eroshenko , V. N. Lukash , E. V. Mikheeva , S. V. Pilipenko , M. V. Tkachev

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

In the interstellar clouds, molecular hydrogens are formed from atomic hydrogen on grain surfaces. An atomic hydrogen hops around till it finds another one with which it combines. This necessarily implies that the average recombination…

Astrophysics · Physics 2009-11-13 Sandip Kumar Chakrabarti , Ankan Das , Kinsuk Acharyya , Sonali Chakrabarti

Hydrogen-burning is the root cause of the star-to-star abundance variations of light nuclei in Galactic globular clusters (GC). In the present work we constrain the physical conditions that gave rise to the observed abundance patterns of…

Astrophysics · Physics 2009-11-13 Nikos Prantzos , Corinne Charbonnel , Christian Iliadis

We calculate the recombination spectra of the He-like ions He~I, C~V, N~VI, O~VII, Ne~IX, Mg~XI, Si~XIII, S~XV, Ar~XVII, Ca~XIX, and Fe~XXV. We include the following physical processes: radiative recombination, dielectronic recombination,…

Astrophysics · Physics 2009-10-31 M. A. Bautista , T. R. Kallman

Cosmological parameter measurements from CMB experiments such as Planck, ACTpol, SPTpol and other high resolution follow-ons fundamentally rely on the accuracy of the assumed recombination model, or one with well prescribed uncertainties.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Marzieh Farhang , J. Richard Bond , Jens Chluba

The existence of a second Higgs doublet in Nature could lead to a cosmological first order electroweak phase transition and explain the origin of the matter-antimatter asymmetry in the Universe. We obtain the spectrum and properties of the…

High Energy Physics - Phenomenology · Physics 2014-11-26 G. C. Dorsch , S. Huber , K. Mimasu , J. M. No

We determine the cosmic abundance of molecular hydrogen (H2) in the local universe from the xCOLD GASS survey. To constrain the H2 mass function at low masses and correct for the effect of the lower stellar mass limit of 10^9 Msun in the…

Astrophysics of Galaxies · Physics 2020-10-14 Thomas J. Fletcher , Amelie Saintonge , Paula S. Soares , Andrew Pontzen

Some astrophysical observations of molecular hydrogen point to a broadening of the velocity distribution for molecules at excited rotational levels. This effect is observed in both Galactic and high redshift clouds. Analysis of H_2, HD, and…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-21 S. A. Balashev , D. A. Varshalovich , A. V. Ivanchik
‹ Prev 1 8 9 10 Next ›