A r A S   N e w s

 

 

N E W S L E T T E R   OF  THE

ARMENIAN ASTRONOMICAL SOCIETY   ( A r A S )

 

No. 9   (March 31, 2004)

 

 

 

Editor: T.Yu.Magakian, tigmag@sci.am

 

 

 

The ArAS Newsletter in the INTERNET:   http://www.aras.am

 

 

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CONTENTS:

 

1) Administrative changes in Byurakan

2) Announcement about the ArAS III Annual Meeting

3) Announcement about the ArAS Annual Prize for Young Scientists

4) The Digitized First Byurakan Survey (DFBS)

5) Contact information

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ADMINISTRATIVE CHANGES IN BYURAKAN

 

In October 2003, the position of the Byurakan Astrophysical Observatory director was announced vacant. Three candidates were nominated firstly to fill the vacancy but Prof. Elma Parsamian and Prof. Arthur Nikoghossian refused their consent and only Dr. Haik Harutyunian agreed to be voted for the position. However the elections did not happen till the mid February and the Presidium of the Armenian National Academy of Sciences decided to appoint Dr. Harutyunian to this position on February 20. He was requested to represent the new staff of the academic council, which is done already. At present the package of suggestions on the further development of the observatory is prepared to be approved by the academic council and the Presidium of NAS. We are going to tell ArAS members in the Newsletter all the news concerning the administrative or other important changes in Byurakan. We hope also that the appointment of Dr. Harutyunian, one of the Co-presidents of our society, to the position of the BAO director will tighten connections between the observatory and ArAS.

 

Announcement about the ArAS III Annual Meeting

 

The ArAS III Annual Meeting will be held on the last fortnight week of August this year in Byurakan. ArAS and the Byurakan Astrophysical Observatory (BAO) will organize it jointly.

 

The Meeting will cover all astronomical topics to allow the participation of all interested scientists, including Solar, stellar and extragalactic astronomy, theoretical astrophysics and astronomical instrumentation.

 

The Organizing Committee includes H.Harutyunian, T.Magakian, A.Mickaelian, T.Movsessian, and E.Nikoghossian.

 

Important! We need to know beforehand if scientists from other than Armenia countries plan to participate to make corresponding arrangements. Please contact OC before April 30.

 

To register, please send your personal data and the title of your contribution to OC before June 30.

 

Contact: elena@bao.sci.am (Elena Nikoghossian)

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Announcement about the ArAS Annual Prize for Young Scientists

 

ArAS is pleased to announce the establishment of its Annual Prize for Young Scientists. The prize will be awarded to a young scientist under 35 working in astronomy or related field and showing significant results in research and/or other scientific activities connected anyhow with the Armenian astronomy.

 

Nominations may be made by ArAS members or any research organization from Armenia or elsewhere and should be sent to one of the ArAS Co-Presidents. They should include personal data for the nominee and a brief description of his/her achievements during the year, including important scientific results, all published papers, participation in meetings, given talks, etc., whatever is considered to be important.

 

The deadline for applications is December 1. A special committee will make the selection and the results will be announced in the last issue of ArAS Newsletter at the end of each year. A diploma and sum of $100 will be awarded to the winner.

 

ArAS Co-President Prof. Yervant Terzian is sponsoring the first ArAS Annual Prize for Young Scientists. There is a suggestion to name the prize after B.E.Markarian.

 

There are plans to establish an ArAS Annual Prize for outstanding scientists as well (V.A.Ambartsumian Prize).

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The Digitized First Byurakan Survey (DFBS)

 

The Armenian astronomers, as well as the whole astronomical community through Internet will have the Digitized First Byurakan Survey (DFBS) very soon. This project is being carried out by the Byurakan Astrophysical Observatory (Armenia) in collaboration with the Cornell University (USA) and Universita di Roma "La Sapienza" (Italy).

 

The First Byurakan Survey (FBS) is the largest spectroscopic survey covering 17,008 sq. degrees at high galactic latitudes (|b|>15). FBS has been carried out by B.Markarian, V.Lipovetski and J.Stepanian in 1965-1980 with the Byurakan Observatory 1m Schmidt telescope using 1.5 deg. prism. 1874 photographic plates in 1139 fields (4x4 deg. each) have been obtained. The dispersion is 1800A/mm near H-gamma, and the limiting magnitude is 17.5-18. Some 20,000,000 spectra are present in the whole survey covering a range 3400-6900A thus giving important information especially on the nature of all these objects.

 

The FBS was conducted originally for search for galaxies with UV-excess (UVX): 1500 such galaxies have been discovered. Their study brought to discovery of many new Seyferts and their first spectral classification, as well as to the definition of starburst galaxies. Markarian survey was the first systematic survey for AGNs, it was a new method of search for AGNs. Two catalogs of Markarian galaxies have been published (Mazzarella & Balzano 1986; Markarian et al. 1989). A few other projects have been fulfilled on the basis of FBS, including the survey for blue stellar objects and late-type stars, optical identifications of IRAS point sources. They allowed discover thousands of new interesting objects, including new bright QSOs, other types of AGN, white dwarfs, subdwarfs, cataclysmic variables, carbon stars, etc.

 

The FBS digitization project is active since 2002. All 1874 plates have been scanned during 2002-2003 with an EPSON EXPRESSION 1680 Pro scanner. The program "scanfits" allowed to write directly the resulting image in FITS format with corresponding information on the plate in its header. The scanner gave data numbers (DN) in the range 0 (dark) to 16383 (transparent) corresponding to a 4.2 dynamic range. The scanning resolution was 1600 dpi, giving a pixel size of 15.875 microns corresponding to 1.542", and the width of spectra occupies ~5 pixels. The length of an FBS spectrum is ~1.7mm, thus we have obtained 107 pixels along the wavelength scale, giving 32.7 A/pix average dispersion. A 175 MB file has been obtained for each FBS plate. The whole database is written onto 85 DVDs and its parts are already available on request.

 

Data reduction includes plate solution (pixels-to-coordinates conversion), wavelength calibration (pixel-to-wavelengths conversion), and intensity and flux calibration (DN-to-I and I-to-flux conversion). A procedure to make the plate solution for the DFBS plates uses the Tycho catalog stars and IRAF. It is a manual process in a two-step procedure, including the identification of 20-25 bright stars from the Tycho catalogue and a preliminary plate solution, and then automatic identification of all Tycho stars present in the field and refinement of the first solution. The final solution is computed and written in the FITS header. The positional accuracy obtained is typically 1 pixel rms, quite sufficient for safe object identification.

 

The extraction, wavelength, density and flux calibration procedures are being worked out as well and will be applied for the DFBS plates to obtain maximum possible information. A classification scheme will be created to distinguish objects of various nature such as QSO/AGN, galaxies, white dwarfs, carbon stars, stars of different spectral types, etc. Template spectra will be made up and search for new objects will be possible.

 

Finally, the DFBS catalog and database with positional, photometric and spectral information on some 20,000,000 objects will be created. The DFBS and the corresponding software will be written on DVDs and distributed to the main astronomical centers, as well as will be available through Internet from the DFBS web page which is in the process of creation too.

 

A few new research projects based on the DFBS have been put forward such as searches for faint Markarian galaxies, new bright QSOs and Seyferts, new white dwarfs and cataclysmic variables, faint carbon stars, optical identifications of radio, IR, and X-ray sources, etc. The DFBS may become a basis for the Armenian Virtual Observatory and a significant contribution to the International Astrophysical Virtual Observatories, especially for its unique spectral information.

 

The DFBS community:

A.Mickaelian, L.Sargsyan, L.Erastova, S.Balayan, K.Gigoyan, L.Hovhannisyan (BAO);

D.Weedman, J.Houck, D.Barry, B.Brandl (Cornell);

R.Nesci, D.Trevese, C.Rossi, S.Sclavi, S.Gaudenzi, E.Massaro (Roma).

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CONTACT INFORMATION

 

Address:           Byurakan Astrophysical Observatory (BAO), Byurakan 378433,

                        Aragatzotn province, ARMENIA

 

Tel/fax:            +374-1 53-27-51 (Areg Mickaelian)

E-mail:             aras@web.am, aras_org@freenet.am

Web page:                   http://www.aras.am