A large-scale variability survey for the northern Galactic plane: KISOGP

2017 ◽  
Vol 13 (S334) ◽  
pp. 335-336
Author(s):  
Noriyuki Matsunaga ◽  
Keyword(s):  
Data Analysis ◽  
Initial Data ◽  
Large Scale ◽  
Galactic Plane ◽  
Variable Stars ◽  
Wide Field ◽  
Schmidt Telescope ◽  
Large Scale Survey

AbstractWe have conducted a large-scale survey of variable stars in the northern Galactic plane, about 320 square degrees using Kiso Wide Field Camera attached to the 105-cm Schmidt telescope at Kiso observatory. In the KISOGP (KWFC Intensive Survey of the Galactic Plane), we collected 40–100 epoch I-band images between 2012 and 2017. In our survey region roughly 5 million stars exist down to the limiting magnitude of ~16.5 mag in I. In the initial data analysis, we detected a couple of thousands of variable stars including approximately 100 Cepheids and more than 700 Miras. More than 80 percents of them were not previously reported as variable stars, indicating that there are still many relatively bright variables to be found in the Galactic plane.

Fibre Optics at the UK Schmidt Telescope

1984 ◽  
Vol 5 (4) ◽  
pp. 579-580 ◽  
Author(s):  
F. G. Watson ◽  
J. A. Dawe
Keyword(s):  
Large Scale ◽  
Variable Stars ◽  
Schmidt Telescope ◽  
General Survey ◽  
Surface Distribution ◽  
Fibre Optics ◽  
Redshift Surveys ◽  
Information Advantage ◽  
The Uk ◽  
Very High

The four-fold advantage over a conventional 4 m reflector which naive information theory confers on the 1.2 m UK Schmidt telescope (Dawe and Watson 1982, Watson 1983) is only approachable in practice under certain rather specific conditions. These relate principally to the surface distribution on the sky of the object classes of interest, and the type of detection employed. Clearly, for general survey work with sky-limited photographic detection, the information advantage is high, but it can be demonstrated (Dawe and Watson 1983) that the relatively new technique of multi-object fibre-optics spectroscopy (eg Hill et al. 1980, 1982, Gray 1983, Lund and Enard 1983) with linear detectors offers very high potential in certain regimes of operation. In particular, the UK Schmidt telescope (UKST) equipped with 400 fibre channels has four times the effective light grasp (= number of fibres utilized × aperture) of a 4 m reflector (with a 1 deg field and equipped with any number of fibres) for target objects with surface densities between approximately 1 and 10 per square degree (Dawe and Watson 1983). Objects ranging from galactic variable stars to quasars lie within these limits, but of especial interest are galaxies, whose apparent luminosity function in this range of surface densities runs from magnitudes 15 to 17 (MacGillivray, private communication). Large-scale, medium accuracy (60 km s−1) redshift surveys of galaxies within this magnitude range promise to be extremely fruitful (Davis 1982) and are easily within the reach of the UKST fibre-coupled to a CCD spectrograph (Watson and Dawe 1984).

scholarly journals Mapping large-scale diffuse γ-ray emission in the 10−100 TeV band with Cherenkov telescopes

2020 ◽  
Vol 637 ◽  
pp. A44 ◽  
Author(s):  
A. Neronov ◽  
D. Semikoz
Keyword(s):  
Large Scale ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
Field Of View ◽  
Medium Size ◽  
Wide Field ◽  
Galactic Latitude ◽  
Cherenkov Telescopes ◽  
Diffuse Flux ◽  
Astrophysical Neutrino

Context. Measurement of diffuse γ-ray emission from the Milky Way with Imaging Atmospheric Cherenkov Telescopes (IACT) is difficult because of the high level of charged cosmic ray background and the small field of view. Aims. We show that such a measurement is nevertheless possible in the energy band 10−100 TeV. Methods. The minimal charged particle background for IACTs is achieved by selecting the events to be used for the analyses of the cosmic ray electrons. Tight cuts on the event quality in these event selections allow us to obtain a sufficiently low background level to allow measurement of the diffuse Galactic γ-ray flux above 10 TeV. We calculated the sensitivities of different types of IACT arrays for the Galactic diffuse emission measurements and compared them with the diffuse γ-ray flux from different parts of the sky measured by the Fermi Large Area Telescope below 3 TeV and with the astrophysical neutrino signal measured by IceCube telescope. Results. We show that deep exposure of existing IACT systems is sufficient for detection of the diffuse flux from all the Galactic Plane up to Galactic latitude |b| ∼ 5°. The Medium Size Telescope array of the CTA will be able to detect the diffuse flux up 30° Galactic latitude. Its sensitivity will be sufficient for detection of the γ-ray counterpart of the Galactic component of the IceCube astrophysical neutrino signal above 10 TeV. We also propose that a dedicated IACT system composed of small but wide-field-of-view telescopes could be used to map the 10−100 TeV diffuse γ-ray emission from across the whole sky. Conclusions. Detection and detailed study of diffuse Galactic γ-ray emission in the previously unexplored 10−100 TeV energy range is possible with the IACT technique. This is important for identification of the Galactic component of the astrophysical neutrino signal and for understanding the propagation of cosmic rays in the interstellar medium.

Progress in Galaxy Redshift Surveys using FLAIR

1992 ◽  
Vol 10 (1) ◽  
pp. 12-15
Author(s):  
F. G. Watson ◽  
A. Broadbent ◽  
D. Hale-Sutton ◽  
T. Shanks ◽  
Q. A. Parker ◽  
...  
Keyword(s):  
Large Scale ◽  
Hubble Constant ◽  
Status Report ◽  
Limited Area ◽  
Schmidt Telescope ◽  
Redshift Surveys ◽  
Development Period ◽  
Galaxy Redshift ◽  
Large Scale Survey ◽  
Spectroscopy System

AbstractAmong the most important stimuli for developing the FLAIR multi-object spectroscopy system on the 1.2-m UK Schmidt Telescope was its potential for carrying out large-scale redshift surveys of galaxies of intermediate magnitude (B <~ 17). During FLAIR’s lengthy development period, these objects provided the yardstick by which the system’s performance was measured, and a number of limited-area redshift surveys were carried out. We are now following these with a 1-in-3 survey over the 60 fields of the ROE/Durham Galaxy Catalogue to produce a redshift map of some 4000 galaxies out to a distance of ~ 300h−1 Mpc (where the parameter h is the Hubble constant expressed as a fraction of 100 kms−1 Mpc−1). In this paper we summarise the results from our redshift surveys to highlight the capabilities of FLAIR. We present a status report on the current large-scale survey, and show that the recently-introduced FLAIR II system will speed its progress considerably.

scholarly journals Wide-Field Observations of Variable Stars in the Region of NGC 7129

1994 ◽  
Vol 161 ◽  
pp. 475-477
Author(s):  
E.H. Semkov
Keyword(s):  
Variable Stars ◽  
Astronomical Observatory ◽  
Flare Star ◽  
Wide Field ◽  
Field Observations ◽  
Schmidt Telescope ◽  
Bulgarian Academy ◽  
Star Forming ◽  
Star Forming Regions ◽  
Academy Of Sciences

During our programme for nonstable and flare star investigations in the star forming regions, more than 290 UBVR photographic plates in the field of the bright nebula NGC 7129 were obtained. The photographic observations were made with the 50/70/172 cm Schmidt telescope of the Rozhen Astronomical Observatory of the Bulgarian Academy of Sciences during the period September 1984–July 1993.

scholarly journals A Large-Scale Survey for Variable Stars in M 33

2009 ◽  
Vol 38 ◽  
pp. 125-132
Author(s):  
D. Bersier ◽  
J.D. Hartman ◽  
K.Z. Stanek ◽  
J.-P. Beaulieu ◽  
J. Kaluzny ◽  
...  
Keyword(s):  
Large Scale ◽  
Variable Stars ◽  
Large Scale Survey

scholarly journals Okayama Astrophysical Observatory Wide-Field Camera

2019 ◽  
Vol 71 (6) ◽  
Author(s):  
Kenshi Yanagisawa ◽  
Yasuhiro Shimizu ◽  
Kiichi Okita ◽  
Daisuke Kuroda ◽  
Hironori Tsutsui ◽  
...  
Keyword(s):  
Focal Plane ◽  
Near Infrared ◽  
Galactic Plane ◽  
Focal Plane Array ◽  
Variable Stars ◽  
Field Of View ◽  
Wide Field

Abstract We report on the development of a wide-field near-infrared (0.9–2.5$\, \mu$m) camera built as a renewal of the existing classical Cassegrain 0.91 m telescope at Okayama Astrophysical Observatory. The optics system was replaced with fast hybrid optics (f/2.5) composed of forward Cassegrain optics and quasi-Schmidt optics, which results in an effective image circle of 52 mm diameter on the focal plane. The new camera, called the Okayama Astrophysical Observatory Wide-Field Camera (OAOWFC), has imaging capabilities in the $Y$, $J$, $H$, and $K_{\rm s}$ bands over a field of view of $0.^{\!\!\!\circ }47 \times 0.^{\!\!\!\circ }47$ with a HAWAII-1 HgCdTe PACE focal plane array. The primary purpose of OAOWFC is to search for variability in the Galactic plane in the $K_{\rm s}$ band and to promptly follow up transients. We have demonstrated a photometric repeatability of 2% in the densest field in the northern Galactic plane and successfully discovered previously unreported variable stars. The observations of OAOWFC are fully autonomous, and we started scientific operations in 2015 April.

scholarly journals Wide-Field Stellar Statistics from Tautenburg Schmidt Plates

1994 ◽  
Vol 161 ◽  
pp. 441-443
Author(s):  
E. Schilbach ◽  
R.-D. Scholz ◽  
S. Hirte
Keyword(s):  
Galactic Plane ◽  
Focal Length ◽  
Photometric Data ◽  
Wide Field ◽  
Plate Bending ◽  
Proper Motions ◽  
Schmidt Telescope ◽  
Positional Accuracy ◽  
Wide Range ◽  
Enormous Amount

For a detailed investigation of the kinematics of our Galaxy we need accurate proper motions and photometric data of stars over a wide range of magnitudes. The proper motions have to be obtained with respect to an extragalactic, i.e. nonrotating reference system. The best way to determine absolute proper motions of a great number of stars for further statistical analysis is to use the enormous amount of information stored on photographic plates taken with large Schmidt telescopes within the last decades. Since automated measuring machines have become available it is no longer a problem to extract this information from a Schmidt plate. Large Schmidt plates cover a sky area of more than 30 square degrees with usually thousands of stars and hundreds of galaxies per square degree outside the galactic plane. With the Tautenburg Schmidt telescope (134/200/400) more than 8000 plates have been taken in selected Northern sky areas since it was mounted in 1960. A 24 cm × 24 cm Tautenburg plate covers a field of about 10 square degrees, and a 20 minute exposure of a B plate has a limiting magnitude of 19 to 21. In comparison to other large Schmidt telescopes the plate bending is reduced to a minimum due to the four metre focal length and the use of relatively small plates. Therefore irregular positional shifts of the emulsion caused by the rebending after the exposure are of less influence. The large focal length leads to a plate scale of 51 arcsec/mm providing a relatively high positional accuracy.

scholarly journals A Deep Wide-Field Survey from Digitally Stacked Schmidt Plates

1994 ◽  
Vol 161 ◽  
pp. 177-181
Author(s):  
M.R.S. Hawkins
Keyword(s):  
Large Scale ◽  
Field Survey ◽  
Monitoring Programme ◽  
Wide Field ◽  
Schmidt Telescope ◽  
Large Numbers ◽  
The Uk

Over the last 18 years or so a large-scale monitoring programme has been undertaken with the UK 1.2 m Schmidt telescope in field 287 at 21h 28m, −45 deg. Plates have been taken over all timescales from 1 hour to 17 years in red and blue passbands, and large numbers of plates have also been taken in other passbands to give deep coverage in U, B, V, R and I. The field is calibrated with some 200 CCD and photoelectric standards, and covers approximately 25 square degrees.

scholarly journals The Galactic Center at 327 MHz

2002 ◽  
Vol 199 ◽  
pp. 268-271
Author(s):  
T.N. LaRosa ◽  
Namir E. Kassim ◽  
T. Joseph W. Lazio ◽  
S.D. Hyman
Keyword(s):  
Large Scale ◽  
Galactic Center ◽  
Galactic Plane ◽  
Dynamic Range ◽  
Small Diameter ◽  
Critical Issue ◽  
Wide Field ◽  
Origin And Evolution ◽  
Extended Sources ◽  
Sgr A

Figure 1 presents a wide-field, high dynamic-range, 327 MHz VLA2 image of the Galactic center (GC). This image was constructed from archival VLA data using new 3-D image restoration techniques which resolve the problem of non-coplanar baselines encountered at long wavelengths. In a recent paper (LaRosa et al. 2000) we presented a catalog of over a hundred sources from this image, 23 extended sources and 78 small-diameter sources. The catalog contains flux densities, positions, sizes, and, where possible, a 20/90 cm spectral index. We also present subimages of all the extended sources. We refer the reader to LaRosa et al. (2000) for the details. In this note we will concentrate on observations of the nonthermal filaments and briefly describe a new model for their formation.The origin and evolution of the nonthermal filaments (NTFs) observed in the GC is an outstanding problem. All of the 7 classified NTFs are visible on Figure 1: Four of these are labeled threads, the other three are the “Snake,” the “Pelican,” and the Sgr C filament. The wide-field imaging at 327 MHz lead to the discovery of the “Pelican” (Lang et al. 1999). This filament has the distinction of being the farthest NTF in projection from Sgr A and the only NTF that is parallel to the Galactic plane. One critical issue for understanding the activity and overall structure of the GC is whether these filamentary sources trace a pervasive, large-scale magnetic field or are local independent structures (e.g., Yusef-Zadeh 1989; Morris 1994, 1996; Uchida & Gusten 1995; Yusef-Zadeh, Wardle & Parastaran 1997; Shore & LaRosa 1999; Lang et al. 1999; Lang, Morris & Echevarria 1999; LaRosa et al. 2000).

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