scholarly journals Symbiotic stars and other Hα emission-line stars towards the Galactic bulge★

2013 ◽  
Vol 432 (4) ◽  
pp. 3186-3217 ◽  
Author(s):  
Brent Miszalski ◽  
Joanna Mikołajewska ◽  
Andrzej Udalski
Keyword(s):  
Emission Line ◽  
Symbiotic Stars ◽  
Galactic Bulge ◽  
Hα Emission

scholarly journals Spectral Line Variations of Symbiotic Stars EG And, AG Dra, and BX Mon and Its Interpretation

2012 ◽  
Vol 8 (S290) ◽  
pp. 353-354
Author(s):  
Tae Seog Yoon ◽  
Soo Hyun Kim ◽  
Hyeonwoo Moon ◽  
Kyu-Seob Kim ◽  
Hyungil Oh
Keyword(s):  
High Resolution ◽  
Spectral Line ◽  
Emission Line ◽  
Emission Lines ◽  
Symbiotic Stars ◽  
Astronomy Observatory ◽  
Echelle Spectrograph ◽  
Balmer Lines ◽  
Hα Emission ◽  
Optical Astronomy

AbstractWe present some results obtained by high resolution spectroscopic observations for symbiotic stars EG And, AG Dra, and BX Mon in recent years which were performed with 1.8-m reflector and echelle spectrograph BOES at Bohyunsan Optical Astronomy Observatory, Youngcheon, South Korea. The variations of Hα emission line during a night and the variations of H Balmer lines and He I emission lines among several analyzed lines over months and years are shown and discussed.

scholarly journals The Orbital Period of the Galactic Z Source Sco X-2

1996 ◽  
Vol 158 ◽  
pp. 365-366
Author(s):  
K. A. Southwell ◽  
J. Casares ◽  
P. A. Charles
Keyword(s):  
Emission Line ◽  
Orbital Period ◽  
Spectroscopic Data ◽  
Galactic Bulge ◽  
Optical Counterpart ◽  
Companion Star ◽  
Hα Emission ◽  
Orbital Periods ◽  
Z Sources

AbstractSco X-2 is a bright Galactic bulge Z source, whose optical counterpart was discovered in 1990 [?], and observed to exhibit strong Hα emission. We have therefore obtained spectroscopic data in order to determine the orbital period and investigate the nature of the companion star. From an analysis of the Hα emission line velocities, we find a most likely orbital period of 13.94 d. This implies an evolved companion, and is consistent with the currently known orbital periods in other Z sources.

Anomalous Hα Emission Line Profile Detected at the Center of DDO 53

2021 ◽  
Vol 919 (2) ◽  
pp. 73
Author(s):  
Justin A. Kader ◽  
Liese van Zee ◽  
Kristen B. W. McQuinn ◽  
Laura C. Hunter
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Hα Emission ◽  
Emission Line Profile

scholarly journals The X-Ray Nova GRO J0422+32 in Decline and Quiescence

1996 ◽  
Vol 158 ◽  
pp. 399-400
Author(s):  
M. R. Garcia ◽  
P. J. Callanan ◽  
J. E. McClintock ◽  
P. Zhao
Keyword(s):  
Emission Line ◽  
Emission Region ◽  
Dwarf Novae ◽  
X Ray ◽  
First Order ◽  
Band Emission ◽  
Line Region ◽  
Hα Emission ◽  
The Stability ◽  
The Continuum

We have followed the X-ray nova GRO J0422+32, spectroscopically and photometrically, throughout the decline to quiescence.In the final stages of decay (days 430…880 after the outburst, see Callanan et al. (1995) for the epoch 1995), the equivalent width (EW) of the Hα emission increases monotonically and the R magnitude decreases monotonically. This suggests that the flux in the Hα line is constant, while the continuum fades. The Hα flux is the product of the R band flux (F(R), arbitrarily scaled to 100 at R = 19 mag) and the EW, and is shown in the last column of the table below. The Hα flux varies by only ~ 30% while the continuum fades by a factor of eight (from R = 19 mag to R = 21.3 mag). So, to first order, the Hα luminosity is constant in the final stages of decay. While it is generally the case that the emission line EWs in individual dwarf novae also increase during the decay, the exact behavior seen in GRO J0422+32 is not what is seen for dwarf novae (on average). Using the relation between EW[Hβ] and Mv given in figure 6 of Patterson (1984), we would expect a factor of ~ 5 variation in the Hα flux during days 430…880. The stability of the Hα flux implies that somehow the emission line region is ‘disconnected’ from the continuum (R–band) emission region.

Optical emission line profiles of symbiotic stars

1989 ◽  
pp. 85-86 ◽  
Author(s):  
K. Robinson ◽  
M. F. Bode ◽  
J. Meabum ◽  
M. J. Whitehead
Keyword(s):  
Emission Line ◽  
Optical Emission ◽  
Symbiotic Stars ◽  
Line Profiles

scholarly journals Study of a Complete Sample of Hα Emission–Line Galaxies from the UCM Survey

1996 ◽  
Vol 171 ◽  
pp. 380-380 ◽  
Author(s):  
J. Gallego ◽  
J. Zamorano ◽  
M. Rego ◽  
A.G. Vitores ◽  
O. Alonso
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Energy Output ◽  
University Of Michigan ◽  
Complete Sample ◽  
Star Forming ◽  
The Galaxy ◽  
Hα Emission ◽  
Emission Line Galaxies ◽  
Galaxy Population

The Universidad Complutense de Madrid survey is a long-term project with the aim of finding and analyzing star forming galaxies using the Hα line as the tracer for star formation processes. In order to obtain a representative and complete sample of the population detected, spectroscopic observations were carried out for the full sample of Hα emission-line galaxy (ELG) candidates of the UCM lists 1 and 2. The ELGs types most commonly found (47%) are intermediate to low-luminosity objects with a very intense star-formation region which dominates the optical energy output of the galaxy. This kind of ELGs is similar to the galaxy population detected in the blue objective-prism surveys. And what is more important, a second population (43%) of star-forming galaxies with low ionization or high extinction properties has been found. This ELGs group is detected neither in the blue (University of Michigan survey, Case survey) nor in other surveys (Kiso, IRAS, Markarian) using other selection techniques.

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