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Related papers: AlH lines in the blue spectrum of Proxima Centauri

200 papers

We present a detailed analysis of a high resolution spectrum of the damped Ly$\alpha$ system at $z_{\rm abs}$~=~2.8112toward PKS~0528-250. The absorption redshift is slightly larger than the emission redshift of the quasar. We estimate the…

Astrophysics · Physics 2007-05-23 R. Srianand , P. Petitjean

Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, alpha, and the proton-to-electron mass ratio, mu = m_p/m_e, as…

We report the discovery of significant linear polarization (p > 1%) in the hyperluminous z=3.87 BALQSO APM~08279+5255. The polarization spectrum is complex, with properties similar to those of other, lower redshift but more highly polarized…

Astrophysics · Physics 2009-10-31 Dean C. Hines , Gary D. Schmidt , Paul S. Smith

The precise mechanisms that provide the non-radiative energy for heating the chromosphere and the corona of the Sun and those of other stars constitute an active field of research. By studying stellar chromospheres one aims at identifying…

The APM multicolor survey for bright z > 4 objects, covering 2500 deg^2 of sky to m(R)~19, resulted in the discovery of thirty-one quasars with z > 4. High signal-to-noise optical spectrophotometry at 5A resolution has been obtained for the…

Astrophysics · Physics 2009-10-28 L. J. Storrie-Lombardi , R. G. McMahon , M. J. Irwin , C. Hazard

We present modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…

High Energy Astrophysical Phenomena · Physics 2015-05-30 C. Jin , M. Ward , C. Done , J. M. Gelbord

We explore the possibility of resolving an image of a damped Lyman alpha (DLA) system in absorption against an extended, diffuse background X-ray source. Typical columns of neutral hydrogen in DLAs are high enough to block out up to ~30% of…

Astrophysics · Physics 2009-11-10 Mark Dijkstra , Zoltan Haiman , Caleb Scharf

We present direct estimates of the mean sky brightness temperature in observing bands around 99GHz and 242GHz due to line emission from distant galaxies. These values are calculated from the summed line emission observed in a blind, deep…

Astrophysics of Galaxies · Physics 2016-12-14 C. L. Carilli , J. Chluba , R. Decarli , F. Walter , M. Aravena , J. Wagg , G. Popping , P. Cortes , J. Hodge , A. Weiss , F. Bertoldi , D. Riechers

We observed the X-ray binaries CirX-1, ScoX-1, GRS 1915+105, GX13+1, and CygX-1 with the Atacama Large Millimeter/submillimeter Array (ALMA). Unresolved continuum emission is found at the positions of all the sources at a frequency of 92…

High Energy Astrophysical Phenomena · Physics 2021-06-09 M. Díaz Trigo , D. Petry , E. Humphreys , C. M. V. Impellizzeri , H. B. Liu

Proxima Centauri (Cen) has been the subject of many flaring studies due to its proximity and potential to host habitable planets. The discovery of millimeter flares from this M dwarf with ALMA has opened a new window into the flaring…

We report the serendipitous discovery of two objects close in projection with fairly strong emission lines at long wavelength (~9190 A). One (A) seems not to be hosted by any galaxy brighter than V(555)=27.5, or I(814)=26.7 (Vega-based…

Astrophysics · Physics 2009-10-31 Daniel Stern , Andrew J. Bunker , Hyron Spinrad , Arjun Dey

Potassium hydroxide (KOH) and sodium hydroxide (NaOH) are expected to occur in the atmospheres of hot rocky super-Earth exoplanets but a lack of spectroscopic data is hampering their potential detection. Using robust first-principles…

Earth and Planetary Astrophysics · Physics 2021-03-03 A. Owens , J. Tennyson , S. N. Yurchenko

Line lists for the sulphur-containing molecules SH (the mercapto radical) and NS are computed as part of the ExoMol project. These line lists consider transitions within the $X$ ${}^2\Pi$ ground state for $^{32}$SH, $^{33}$SH, $^{34}$SH and…

Solar and Stellar Astrophysics · Physics 2018-05-02 Sergei N. Yurchenko , Wesley Bond , Maire N. Gorman , Lorenzo Lodi , Laura K. McKemmish , William Nunn , Rohan Shah , Jonathan Tennyson

Extreme ultraviolet (EUV) spectra emitted from aluminum in the 5-340 A wavelength range were observed in Experimental Advanced Superconducting Tokamak (EAST) discharges. Several spectral lines from aluminum ions with different degrees of…

A theoretical line list for $^{15}$NH$_3$ CoYuTe-15 is presented based on the empirical potential energy and ab initio dipole moments surfaces developed and used for the production of the ExoMol line list CoYuTe for $^{14}$NH$_3$. The…

Aims Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low/medium resolution cannot disentangle the true sky-continuum…

The 1s2-1s2l lines are the most intense He-like ions lines. They are used as spectroscopic diagnostics for solar active regions as well as for different laboratory plasmas. Nowadays, it exits very high spectral resolution instruments and,…

Astrophysics · Physics 2007-05-23 Jacques Dubau , Delphine Porquet

A revised rotation-vibration line list for the combined hydrogen cyanide (HCN) / hydrogen isocyanide (HNC) system is presented. The line list uses {\it ab initio} transition intensities calculated previously (Harris et al., ApJ, 2002, 578,…

Solar and Stellar Astrophysics · Physics 2014-06-27 R. J. Barber , J. K. Strange , C. Hill , O. L. Polyansky , G. Ch. Mellau , S. N. Yurchenko , Jonathan Tennyson

We study H I Lyman-alpha absorption observed by the Hubble Space Telescope toward the nearby binary system Alpha Cen (G2 V+K0 V) and its distant companion star Proxima Cen (M5.5 Ve). Absorption from heliospheric H I heated by the solar…

Astrophysics · Physics 2009-10-31 Brian E. Wood , Jeffrey L. Linsky , Hans-Reinhard Mueller , Gary P. Zank