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June 19, 2008 63 rd OSU Meeting on Molecular Spectroscopy – Columbus, OH1 COMPLETE 2MM SPECTRAL LINE SURVEY (130-170 GHZ) OF SGR B2N, SGR B2OH, IRC +10.

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Presentation on theme: "June 19, 2008 63 rd OSU Meeting on Molecular Spectroscopy – Columbus, OH1 COMPLETE 2MM SPECTRAL LINE SURVEY (130-170 GHZ) OF SGR B2N, SGR B2OH, IRC +10."— Presentation transcript:

1 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH1 COMPLETE 2MM SPECTRAL LINE SURVEY ( GHZ) OF SGR B2N, SGR B2OH, IRC , ORION (KL), ORION-S, W51M AND W3(IRS5) Anthony J. Remijan NRAO Assistant Scientist – ALMA Commissioning Barry E. Turner – In Memoriam NRAO Scientist Diane P. Leigh (University of Virginia) & Andrew J. Markwick-Kemper (University of Manchester) 63rd Ohio State University International Symposium on Molecular Spectroscopy Columbus, OH June 19, 2008

2 63 rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Presentation Outline Survey Overview –Dedication to Barry –Scientific & Technical Justification Accessing the data –Reduced data using SLiSE Initial Survey Results –Composite spectra –Orion KL molecule fits – uncovering new transitions? –Sgr B2N molecule fits – re-confirming interstellar acetone? Future plans/disseminating the data to the community.

3 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Survey Overview Until very recently, this project was entirely the work of Barry E. Turner. He wrote the original proposal and did all of the observing. B.E. Turner passed away on Saturday, May 10 th after a long struggle with Parkinson's Disease. This presentation is a tribute to him and the work he performed on these data and to give further information about the project and important information to the astronomical community who will use these data. We fully expect users of these data to give B.E. Turner and this work the appropriate citation and credit.

4 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Survey Overview Importance of a 2mm Line Survey: At the time of the data collection, no published 2mm survey existed. In addition, high- excitation sources such as Orion the 2mm window will contain more detectable lines (and hence more information) than the 3mm window, because of larger line strengths on average, yet fewer lines than the 1.3mm window. Sources of Interest: SGR B2N, SGR B2OH, IRC , ORION (KL), ORION-S, W51M AND W3(IRS5)‏ From the forgoing, it is obvious that the astrochemistry most interesting regions are Orion KL, Sgr B2N, W51M, and IRC , and the proposal focused primarily on these regions, which occupy complementary positions in the sky. At the time, the overwhelming body of astrochemical knowledge is based on only two sources: Orion(core) and SgrB2(OH). How typical are these sources? However, different positions within each of the sources reveal quite different chemical abundances. Even greater differences appear to exist between entirely different star forming regions such as SgrB2 and Orion. W51M appears to be quite different again. Finally, IRC10216 serves to define the differences between circumstellar and interstellar chemistry.

5 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Survey Overview Observing Strategy: The 2mm SIS junction receiver will be dual channel, and will cover the range GHz with a hoped-for receiver noise temperature of typically < 75K (DBS), with a worse case value of 100K DBS. The receiver is expected to be tunable SSB. The hybrid spectrometer will be used with a bandwidth of 600 MHz, and provide 768 channels for each of the two receivers. The spectral resolution is thus MHz/channel or 1.3 km/s at 150 GHz.

6 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

7 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

8 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Orion(KL): The Orion(KL) spectra are very congested with lines leaving a low incidence of clean lines that can be attributed to a single species. However, with about 1200 lines over the entire frequency range, many species can be identified as undeniably present. Therefore, though many of the lines are likely due to molecular transitions of two or more different species, the shear volume of lines allows for the determination of some of the physical properties of these molecules.

9 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Uncovering New Lines CH 3 OCH 3 : T rot = 75K N t = 6*10 15 cm -2 CH 3 CHO: T rot = 40K N t = 5*10 13 cm -2

10 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Sgr B2N NH 2 CHO: T rot = 75K N t = 5*10 15 cm -2

11 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Sgr B2N CH 3 OCHO: T rot = 150K N t = 3*10 16 cm -2

12 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Sgr B2N CH 3 CHO: T rot = 20K N t = 1.1*10 15 cm -2

13 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Sgr B2N CH 3 OCH 3 : T rot = 145K N t = 4.2*10 16 cm -2

14 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Initial Survey Results Sgr B2N CH 3 COCH 3 : T rot = 70K N t = 2.3*10 15 cm -2

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16 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

17 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

18 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

19 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

20 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

21 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH

22 June 19, rd OSU Meeting on Molecular Spectroscopy – Columbus, OH Accessing the Spectral Line Data The data can be found in electronic form at: The data are distributed using the Spectral Line Search Engine (SLiSE). SLiSE is a data display tool that contains all the fully reduced and calibrated archived data taken as part of this 2mm survey. The only caveat is that SLiSE was built using Java 1.5. So an update to the user's java may be necessary. In addition, SLiSE will work on a Mac running Safari, not Netscape. Systematic errors in line frequencies and relative intensities are sure to exist based on the amount of time over which these data were taken. However, we do not have access to all of B.E. Turner's calibration and data reduction routines. We present the calibrated data using the SLiSE tool. If you are interested in obtaining the raw data from the 12m during this time, we are working on making the fits data available at that same web location through the NRAO single dish data archive. This is currently a work in progress and subsequently may not be available until Fall Any data requests then should be made to Anthony J. Remijan directly at:


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