scholarly journals A 2μm narrow-band survey for emission-line stars in the inner Galaxy

1999 ◽  
Vol 193 ◽  
pp. 472-473
Author(s):  
Robert D. Blum ◽  
Augusto Damineli

We have begun a search for emission-line stars toward the inner Galaxy using narrow-band photometry centered on the emission lines of He I 2.06μm, C IV 2.08μm, H I Brγ 2.166μm and He II 2.189μm. The census of Wolf-Rayet and other emission-line stars in the Galaxy is incomplete, owing to the large extinction at optical and shorter wavelengths toward the inner Galaxy. However, these massive, evolved stars are bright and can be detected at large distances in the near infrared.

2019 ◽  
Vol 15 (S356) ◽  
pp. 12-16
Author(s):  
Silvia Bonoli ◽  
Giorgio Calderone ◽  
Raul Abramo ◽  
Jailson Alcaniz ◽  
Narciso Benitez ◽  
...  

AbstractThe J-PAS survey will soon start observing thousands of square degrees of the Northern Sky with its unique set of 56 narrow band filters covering the entire optical wavelength range, providing, effectively, a low resolution spectra for every object detected. Active galaxies and quasars, thanks to their strong emission lines, can be easily identified and characterized with J-PAS data. A variety of studies can be performed, from IFU-like analysis of local AGN, to clustering of high-z quasars. We also expect to be able to extract intrinsic physical quasar properties from the J-PAS pseudo-spectra, including continuum slope and emission line luminosities. Here we show the first attempts of using the QSFit software package to derive the properties for 22 quasars at 0.8 < z < 2 observed by the miniJPAS survey, the first deg2 of J-PAS data obtained with an interim camera. Results are compared with the ones obtained by applying the same software to SDSS quasar spectra.


2018 ◽  
Vol 477 (1) ◽  
pp. 195-209 ◽  
Author(s):  
Michael S Talbot ◽  
Joel R Brownstein ◽  
Adam S Bolton ◽  
Kevin Bundy ◽  
Brett H Andrews ◽  
...  

Abstract We present a catalogue of 38 spectroscopically detected strong galaxy–galaxy gravitational lens candidates identified in the Sloan Digital Sky Survey IV (SDSS-IV). We were able to simulate narrow-band images for eight of them demonstrating evidence of multiple images. Two of our systems are compound lens candidates, each with two background source-planes. One of these compound systems shows clear lensing features in the narrow-band image. Our sample is based on 2812 galaxies observed by the Mapping Nearby Galaxies at APO (MaNGA) integral field unit (IFU). This Spectroscopic Identification of Lensing Objects (SILO) survey extends the methodology of the Sloan Lens ACS Survey (SLACS) and BOSS Emission-Line Survey (BELLS) to lower redshift and multiple IFU spectra. We searched ∼1.5 million spectra, of which 3065 contained multiple high signal-to-noise ratio background emission-lines or a resolved [O ii] doublet, that are included in this catalogue. Upon manual inspection, we discovered regions with multiple spectra containing background emission-lines at the same redshift, providing evidence of a common source-plane geometry which was not possible in previous SLACS and BELLS discovery programs. We estimate more than half of our candidates have an Einstein radius ≳ 1.7 arcsec, which is significantly greater than seen in SLACS and BELLS. These larger Einstein radii produce more extended images of the background galaxy increasing the probability that a background emission-line will enter one of the IFU spectroscopic fibres, making detection more likely.


1983 ◽  
Vol 71 ◽  
pp. 239-243
Author(s):  
B.R. Pettersen

AbstractLight curves of major stellar flares have been used to study the behavior of U-B, B-V, and V-R. The majority of the flux transmitted through these filters is continuum radiation, but U and B are affected by emission lines. The variability of Ha and H$ emission lines were monitored through narrow band filters. The timescales of emission line variability are considerably longer than those for the continuum, and the emission line flare peak occurs a few minutes after the continuum flare maximum. No variability in lines at a timescale of seconds is detected in our data.


1979 ◽  
Vol 47 ◽  
pp. 151-153
Author(s):  
T. D. Kinman

Four methods for finding emission-line galaxies have been compared. Method (a) uses the ultraviolet excess, as found either by filter photography (Haro 1956) or by objective prism spectra (Markarian 1967). glanco (1974) introduced a thin prism with the CTIO Schmidt (1740 Å mm-1 at Hβ) which with IIIa-J plates [Method (b)] gave enough resolution for Smith (1975) and MacAlpine et al. (1977a, 1977b) to detect and classify galaxies by strong emission lines. Following a suggestion by McCarthy that even higher dispersion might be useful, I have used the CTIO Schmidt with [Method (c)] the 4° prism, a GGl+55 filter and IIIa-J emulsion and with [Method (d)] the 10° prism, an RG630 filter and IIIa-F emulsion. These latter give about 400 Å mm-1 at Hβ and Hα respectively which improves the visibility of emission lines against the galaxy continuum so that [0111] 5007 and 4959 and Hβ can be seen on the green plates and Hα and [SII] 6725 can be seen on the red plates.


2010 ◽  
Vol 6 (S272) ◽  
pp. 606-607 ◽  
Author(s):  
Michelle L. Edwards ◽  
Reba M. Bandyopadhyay ◽  
Stephen S. Eikenberry ◽  
Valerie J. Mikles ◽  
Dae-Sik Moon

AbstractWe survey the environment of Cl 1806-20 using near-infrared narrow-band imaging to search for Brγ features indicative of evolved massive stars. Using this technique, we successfully detect previously identified massive stars in the cluster. We detect no new emission line stars, establishing a firm upper limit on the number of Wolf Rayets and Luminous Blue Variables; however, we do find several candidate OB supergiants, which likely represent the bulk of the heretofore undiscovered massive star population.


2019 ◽  
Vol 14 (S353) ◽  
pp. 130-133
Author(s):  
Sié Zacharie Kam ◽  
Claude Carignan ◽  
Michel Marcelin ◽  
Philippe Amram ◽  
Jean Koulidiati

AbstractWe present observations on optical emission lines acquired with the scanning Fabry-Perot interferometer of the observatoire du Mont Mégantic, of the Andromeda galaxy (M31). A 765 order Fabry-Perot were used with a fast readout EM-CCD. From data obtained, kinematic maps and data points for the rotation curve of the innermost part of the galaxy are derived. Several dozen of regions have been scanned with the Fabry-Perot interferometer and narrow band interference filters. The central 10’x10’ were scanned with five different filters. Observations have been made in order to get better Hα data for kinematics purposes.


2004 ◽  
Vol 193 ◽  
pp. 317-321
Author(s):  
Robert F. Wing ◽  
Kyle M. Walker ◽  
D. Jack MacConnell ◽  
Edgardo Costa

AbstractNarrow-band classification photometry, on a six-color system that measures near-infrared bands of TiO and CN, has been obtained for a set of red supergiants in the Small Magellanic Cloud. To investigate the effects of metallicity on the band-strength indices, comparisons are made to supergiants in the LMC and the Galaxy. Two new variable stars are reported.


1982 ◽  
Vol 70 ◽  
pp. 165-168
Author(s):  
Jiri Grygar ◽  
Drahomir Chochol

The variable emission-line object V1329 Cyg (= HBV 475) was discover red by Kohoutek (1969).Crampton and Grygar (1969) identified more than 100 emission lines in the blue portion of the spectrum, while Andrillat (1969) found evidence for the late-type (M) spectrum in the near infrared. This justified the classification of the object among the symbiotic stars. The classification was subsequently confirmed by all authors who studied the spectroscopic evolution of the object.


2012 ◽  
Vol 8 (S295) ◽  
pp. 159-162
Author(s):  
Oliver Steele ◽  
Daniel Thomas ◽  
Claudia Maraston ◽  
James Etherington ◽  

AbstractWe study the influence of environment on emission line properties using the Galaxy And Mass Assembly (GAMA) survey, taking care to disentangle the role of mass and environment. We look at the role of local density separating galaxies into classifications star forming, AGN, and SF/AGN composite using the BPT diagnostic diagram. We find that environment is generally less important as a driving factor than galaxy mass. The presence of emission lines, whether driven by star formation or central supermassive black hole activity mostly depends on galaxy mass consistently for all galaxy types.


2019 ◽  
Vol 55 (2) ◽  
pp. 351-361 ◽  
Author(s):  
R. Benítez-Álvarez ◽  
F. Martínez-Piñón ◽  
V. G. Orlov

This paper presents the conceptual design for a new method for the suppression of OH emission lines at near-infrared (NIR) wavelengths by actively adjusting the aperiodic fiber optic Bragg gratings tension. First, we prepared an experimental study in which we simulated an OH emission line using a semiconductor laser at 1548.43 nm and a commercial FBG, with a Bragg wavelength of 1547.76 nm. We demonstrated that the grating Bragg wavelength can be adjusted by controlling the linear deformation of the fiber with a force in the range of 0 to 53.88 gf (0.528 N) that provides a sensitivity of 0.014 nm g −1 . Second, we proposed the design of a system connected to the telescope instrumentation, with the different stages that would allow monitoring the suppression of emission lines.


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