balmer decrement

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2020-12-19 · Balmer decrement is discussed resulting in a value of C bd.A comparison of these two values is made in Sect. 4 which leads to a conclusion aboutR V. At the same time C rad is computedand discussed. 2. The infrared spectrum 2.1. Observations We have selected 16 planetary nebulae for measurement which are almost certainly in the Galactic bulge
DUST EXTINCTION FROM BALMER DECREMENTS OF
ties. Balmer decrements are measured using spectroscopy and analyzed down to an Hα ﬂux limit of approximately 5 10−17 erg s−1 cm−2. These are galaxies a factor of approx-imately two fainter than galaxies previously studied at z ∼ 1.5 (Sobral et al. 2012).
The Steep Balmer Decrement of Quasars and Seyfert I
2007-10-1 · Observations of QSOs and Seyfert I galaxies show an anomalously steep Balmer decrement which is in contradiction to the prediction of the traditional recombination theory. This is a long standing puzzle in past three decades in the study of AGNs. In this paper we provide an alternative approach to solve this puzzle by using a newly recognized
Galaxy Properties from the Portsmouth Group SDSS
The latter is estimated through the Balmer decrement between H β and H α when available (Veilleux Osterbrock 1987). However the relatively low signal-to-noise ratios in the BOSS spectra make measurement of the Balmer decrement highly uncertain.
Spectral imaging of proton aurora and twilight at Tromsø
2004-7-13 · 47 Bearing in mind the large uncertainties in the collision cross section the modeled values we derived for the Balmer decrement are close to those obtained in the three previous studies described above. All the modeling Balmer decrement values are however larger than the 2.4 Balmer decrement we observed over Tromsø on 20 January 2002.
Balmer decrement of Sloan Digital Sky Survey galaxies
2011-12-16 · The Balmer decrement determined from the EWs is significantly better than for the full sample and especially so when no correction is included ( Fig. 3 ) with dispersions of 1σ∼ 0.11 0.06 0.05 and 0.04 dex around the 1 1 line respectively for the four binned samples.
Understanding the Discrepancy between IRX
Understanding the Discrepancy between IRX and Balmer Decrement in Tracing Galaxy Dust Attenuation Qin Jianbo ASTROPHYSICAL JOURNAL 2019 886 1 28
Balmer decrement indicates that 1.0 < EB V < 1.4.
Balmer decrement observed by Angerhofer et al. re-quires a large reddening and hence a large distance. Ob-servations of foreground field stars by Angerhofer et al. yield a reddening EB_V < 0.1 for a distance of only 170 pc. Finally the ΣD relationship for the extended non-thermal source indicates a
Exercise 2 Detecting Interstellar Reddening
The Balmer Decrement In the Bohr model of the hydrogen atom there are many distinct energy levels between which electrons can transfer if they emit or absorb the proper amount of energy. Upward moves require absorption of energy while downward ones release energy.
On the anomalous balmer decrement in the orion nebula
2006-9-12 · New measurements of Balmer lines in the central part of the Orion nebula have been made on the 6-m telescope. The generalized curve of the level population is compiled from the Balmer line and radio line measurements. A new approach to the problem of the anomalous Balmer decrement is
The Steep Balmer Decrement of Quasars and Seyfert I
2007-10-1 · Observations of QSOs and Seyfert I galaxies show an anomalously steep Balmer decrement which is in contradiction to the prediction of the traditional recombination theory. This is a long standing puzzle in past three decades in the study of AGNs. In this paper we provide an alternative approach to solve this puzzle by using a newly recognized
1811.11063 Reddening of the BLR and NLR in AGN From a
2018-11-27 · Reddening of the BLR and NLR in AGN From a Systematic Analysis of Balmer Decrement. We selected an active galactic nuclei (AGN) sample () from Sloan Digital Sky Survey Data Release 7 and measured the broad- () and narrow-line Balmer decrements () of 554 selected AGNs. We found that the distributions of Balmer decrements can be fitted by a
--UCAS
8 Reddening of the BLR and NLR in AGNs from a systematic analysis of Balmer decrement Monthly Notices of the Royal Astronomical Society 2019 9 Resolved neutral carbon emission in nearby galaxies CI Lines as Total Molecular Gas Tracers The Astrophysical Journal 2019
A new explanation of the Balmer decrement in quasars
1985-6-17 · The observed very steep Balmer decrement for low red shift quasars has been one of the most important puzzles for many years. The observed intensity ratios of the Balmer line series for QSOs are seriously in disagreement with those for ordinary nebulae.
Balmer decrementShiyin s note
2018-8-2 · HII region case B Balmer recombination decrement Ha/Hb = 2.85 for T = 10 4 K and Ne=10 4 cm-3 (Brocklehurst 1971). Halpha Hbeta Hgamma = 2.8 1.0 0.47 for temperatures near 10 4 °K In AGNs however the harder photoionizing spectrum results in a large transition zone or partly ionized region in which H° coexists with H
Balmer Decrement and Outburst of Symbiotic Stars
Balmer decrement defined by the ratio of spectral intensity defined by I(Hα) /I(Hβ) is applied tentatively to the recent outbursts of three symbiotic stars (AG Peg V 694 Mon and AG Dra). As a result during the outbursts a characteristic feature can be recognized between their brightness change (from AAVSO data base) and the Balmer decrement
MOSDEF Measurements of Balmer Decrements and the
2015-7-17 · Balmer Decrement Measurements 224 star-forming galaxies at z spec = 1.362.59 . Calculating the Attenuation Curve Ratios of Composites . Calculating the Attenuation Curve Normalization (R V) Normalized so that f Q eff (B)-Q eff (B) =
A new explanation of the Balmer decrement in quasars
1985-6-17 · The very steep Balmer decrement one of the most important puzzles in quasars has been satisfactorily explained by use of a new theory of Cerenkov line emission. Volume 109A number 8 PHYSICS LETTERS 17 June 1985 A NEW EXPLANATION OF THE BALMER DECREMENT IN QUASARS T. KIANG Dunsink Observatory Castleknock Dublin 15 Ireland J.H. YOU F.Z
Dust extinction from balmer decrements of star-forming
Interstellar dust extinction is measured from stacked spectra that cover the Balmer decrement (Hα/Hβ). We present dust extinction as a function of Hα luminosity (down to 3 1041 erg s-1) galaxy stellar mass (reaching 4 108 M and rest-frame Hα equivalent width. The faintest galaxies are two times fainter in Hα luminosity than
--UCAS
8 Reddening of the BLR and NLR in AGNs from a systematic analysis of Balmer decrement Monthly Notices of the Royal Astronomical Society 2019 9 Resolved neutral carbon emission in nearby galaxies CI Lines as Total Molecular Gas Tracers The Astrophysical Journal 2019
Understanding the Discrepancy between IRX
Understanding the Discrepancy between IRX and Balmer Decrement in Tracing Galaxy Dust Attenuation Qin Jianbo ASTROPHYSICAL JOURNAL 2019 886 1 28
--UCAS
8 Reddening of the BLR and NLR in AGNs from a systematic analysis of Balmer decrement Monthly Notices of the Royal Astronomical Society 2019 9 Resolved neutral carbon emission in nearby galaxies CI Lines as Total Molecular Gas Tracers The Astrophysical Journal 2019
Note on the intensity decrement in the balmer series
Note on the intensity decrement in the balmer series. Thomas Ralph Merton. Google Scholar. Find this author on PubMed . Search for more papers by this author . and . John William Nicholson. Google Scholar. is afforded by the higher members of the Balmer series of hydrogen. As many as 29 members of this series have been observed by Dyson and
Understanding the Discrepancy between IRX
Understanding the Discrepancy between IRX and Balmer Decrement in Tracing Galaxy Dust Attenuation Qin Jianbo ASTROPHYSICAL JOURNAL 2019 886 1 28
The Balmer decrement of SDSS galaxiesCORE
Yet at high redshifts obtaining such spectra becomes costly. Balmer emission line equivalent widths are much easier to measure requiring only low resolution spectra or even simple narrow band filters and therefore shorter observation times. However a correction for the stellar continuum is still needed for this equivalent width Balmer decrement.
1811.11063 Reddening of the BLR and NLR in AGN From a
2018-11-27 · Reddening of the BLR and NLR in AGN From a Systematic Analysis of Balmer Decrement. We selected an active galactic nuclei (AGN) sample () from Sloan Digital Sky Survey Data Release 7 and measured the broad- () and narrow-line Balmer decrements () of 554 selected AGNs. We found that the distributions of Balmer decrements can be fitted by a
The Balmer decrement in the emission spectra of
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The Balmer decrement in the emission spectra of
The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download.
Galaxy Properties from the Portsmouth Group SDSS
The latter is estimated through the Balmer decrement between H β and H α when available (Veilleux Osterbrock 1987). However the relatively low signal-to-noise ratios in the BOSS spectra make measurement of the Balmer decrement highly uncertain.