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We introduce a method of subtracting geocoronal Halpha emissions from the spectra of LAMOST medium-resolution spectral survey of Galactic nebulae (LAMOST-MRS-N). The flux ratios of the Halpha sky line to the adjacent OH lambda6554 single…

Instrumentation and Methods for Astrophysics · Physics 2021-11-17 Wei Zhang , Hong Wu , Chaojian Wu , Juanjuan Ren , Jianjun Chen , Chih-Hao Hsia , Yuzhong Wu , Hui Zhu , Jianrong Shi , Zhongrui Bai , Zhaoxiang Qi , Yongheng Zhao , Yonghui Hou

We summarize the relationship between the free-free emission foreground and Galactic H-alpha emission. H-alpha observations covering nearly the entire celestial sphere are described. These data provide a template to isolate and/or remove…

Astrophysics · Physics 2008-11-26 P. R. McCullough , J. E. Gaustad , W. Rosing , D. Van Buren

Recently completed H-Alpha surveys of large portions of the sky can be used to create maps of the free-free intensity distribution at high Galactic latitude that are independent of the spectral fits to the CMB data. This provides an…

Astrophysics · Physics 2007-05-23 R. J. Reynolds , L. M. Haffner

We study an undocumented large translucent cloud, detected by means of its enhanced radiation on the SHASSA (Southern H-Alpha Sky Survey Atlas) survey. We consider whether its excess surface brightness can be explained by light scattered…

Astrophysics of Galaxies · Physics 2015-05-19 K. Lehtinen , M. Juvela , K. Mattila

The chromospheric H-alpha spectral line is a strong line in the spectrum of the Sun and other stars. In the stellar regime, this spectral line is already used as a powerful tracer of stellar activity. For the Sun, other tracers (i.e, CaII…

Solar and Stellar Astrophysics · Physics 2022-05-18 A. Diercke , C. Kuckein , P. W. Cauley , K. Poppenhäger , J. D. Alvarado-Gómez , E. Dineva , C. Denker

Large spectroscopic surveys have enabled in the recent years the computation of three-dimensional interstellar extinction maps thanks to accurate stellar atmospheric parameters and line-of-sight distances. Such maps are complementary to 3D…

A 13x13 degree image of Balmer H-alpha emission at galactic latitude -65 degrees is presented. Sensitivity is limited in part by confusion: the peak-to-valley anisotropy of the H-alpha surface brightness is 0.2 Rayleighs on angular scales…

Astrophysics · Physics 2009-10-30 Peter R. McCullough

Characterizing the diffuse Galactic synchrotron emission at arcminute angular scales is needed to reliably remove foregrounds in cosmological 21-cm measurements. The study of this emission is also interesting in its own right. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-27 Samir Choudhuri , Somnath Bharadwaj , Sk. Saiyad Ali , Nirupam Roy , H. T. Intema , Abhik Ghosh

We have carried out a survey searching for H alpha emitting galaxies at z~0.24 using a narrow band filter tuned with the redshifted line. The total sky area covered was 0.19 square degrees within the redshift range 0.228 to 0.255 in a set…

Astrophysics · Physics 2009-11-07 S. Pascual , J. Gallego , A. Aragon-Salamanca , J. Zamorano

The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, HAWC, Tibet, and IceCube. Most notably,…

High Energy Astrophysical Phenomena · Physics 2020-11-03 Julia Becker Tjus , Paolo Desiati , Niklas Döpper , Horst Fichtner , Jens Kleimann , Mike Kroll , Frederik Tenholt

We have completed a robotic wide-angle imaging survey of the southern sky (declination less than +15 degrees) at 656.3 nm wavelength, the H-alpha emission line of hydrogen. Each image of the resulting Southern H-Alpha Sky Survey Atlas…

Astrophysics · Physics 2008-11-26 J. E. Gaustad , P. R. McCullough , W. Rosing , D. Van Buren

We present observations of Galactic H alpha emission along two declination bands where the South Pole cosmic microwave background experiment reports temperature fluctuations. The high spectral resolution of our Fabry-Perot system allows us…

Astrophysics · Physics 2011-05-23 M. Marcelin , P. Amram , J. G. Bartlett , D. Valls-Gabaud , A. Blanchard

Using a sample of dwarf irregular galaxies selected from the ALFALFA blind HI-survey and observed using the VIMOS IFU, we investigate the relationship between H$\alpha$ emission and Balmer optical depth ($\tau_{\text{b}}$). We find a…

We investigate how the typical dust extinction of H-alpha luminosity from a star-forming galaxy depends upon star formation rate (SFR), metallicity and stellar mass independently, using a sample of ~90,000 galaxies from Data Release 7 of…

Astrophysics of Galaxies · Physics 2015-05-19 Timothy Garn , Philip Best

The presence of broad wings in the H$\alpha$ line is commonly used as a diagnostic of the presence and properties of galactic winds from star-forming galaxies. However, the accuracy of this approach has not been subjected to extensive…

Astrophysics of Galaxies · Physics 2026-05-29 Rongjun Huang , Aditi Vijayan , Mark R. Krumholz

This paper reports detections of H$\alpha$ emission and stellar continuum out to approximately 30 physical kpc, and H$\alpha$ directionality in the outskirts of H$\alpha$-emitting galaxies (H$\alpha$ emitters) at $z=0.4$. This research…

Astrophysics of Galaxies · Physics 2022-02-23 Rhythm Shimakawa , Masayuki Tanaka , Satoshi Kikuta , Masao Hayashi

Measurements of the Galactic synchrotron emission is relevant for the 21-cm studies from the Epoch of Reionization. The study of the synchrotron emission is also useful to quantify the fluctuations in the magnetic field and the cosmic ray…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Samir Choudhuri , Abhik Ghosh , Nirupam Roy , Somnath Bharadwaj , Huib. T. Intema , Sk. Saiyad Ali

The shadow is a separated feature in the satellite images specially high resolution images. It may be looked as a problem when it causes a loss in the ground ray response to the shaded area, and may be, from other view, considered as an…

Popular Physics · Physics 2018-03-15 Emad Ali Al-Hilaly , Israa J. Muhsin

This document provides a brief summary estimate of Galactic free-free emission and H-alpha emission and their relationship. Particular emphasis is placed on estimating the potential free-free emission in the region of significant confusion…

Astrophysics · Physics 2007-05-23 George F. Smoot

We present some developments in determining H-alpha distances to high-velocity clouds (HVCs) in the Galactic halo. Until recently, it was difficult to assess the nature and origin of HVCs because so little was known about them. But now…

Astrophysics · Physics 2007-05-23 J. Bland-Hawthorn , P. R. Maloney
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