Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.apo.nmsu.edu/Telescopes/ARCprogress/051214ARC20Anniv/Presentations/History/York_APO.20th.history+DIBs.pdf Дата изменения: Fri Aug 1 18:54:47 2014 Дата индексирования: Sun Apr 10 10:13:56 2016 Кодировка: Поисковые слова: massive stars

APO and Diffuse Interstellar Bands 19822014 Donald G. York University of Chicago
APO 20th (30th ?) reunion May 12, 2014


What are Diffuse Interstellar Bands?
· 570 interstellar lines between 4000A and 8500A (more to the red, developed by SDSS III IR spectrograph). Interstellar because they are staVonary in spectra of spectroscopic binaries. · Known from first 2 discovered in 1919, for 95 years, unidenVfied by type of material or QM system in all that Vme.


· Diffuse: widths >30 km/sec, compared to atomic line widths of 0.3 km/sec · Thought now to be molecular, species not agreed on. · If molecular, the diffuseness would be explained by radiaVve pumping of low lying rotaVonal levels by the Cosmic Microwave Background (as for CN), but many more levels.


The personal story What APO means to me.
1. Thesis on Diffuse Interstellar Bands with Carnegie image tube



of gain 0.1 and photographic plates. Tube was removed and thesis completed. Realized there had to be a beaer way. Dreams of having own large, private telescope to do long programs. I moved to Princeton to have such access (UV).

2. There is prehistory only known by rumor. (1970s)(NMSU, Washington, Howard). 3. Wallerstein talks to Jenkins (an ISM collaborator) at Princeton, Jenkins suggests Wallerstein talk to Ostriker. 4. JPO shows interest but cannot take on the full 1/3 partnership needed.


5. JPO asks me to be point person for Princeton and find out more. Travel to Sunspot, meets Anderson and Balick. 6. York uses Kia Peak 4 meter (1980) to observe DIBs. CCD read noise, 50 electrons. Peer reviewed Vme highly restricVve. 7. John Lowrance, Princeton entrepreneur and engineer, suggests using remote observing using new technology (1400 baud modems) to control telescope from remote sites. Princeton did that with Stratoscope in the 1960s.


8. York moves in 1982 to Chicago, informs colleagues of possibility. 9. Dean Stuart Rice urges astronomers to be more ambiVous and go for the partnership. 10. ConsorVum formed. Washington, Washington State, NMSU, Princeton, Chicago. 1983. Roads started 11. Around 1988, instruments were decided, including an echelle (NSF proposal). 12. 8 years of waiVng, for mirror, instruments, etc. Remote operaVon worked almost out of the box, by 1988, in trial runs.


1998 Echelle on telescope with SDSSSITE 2kx2K CCD, 5 electron read noise. Mirror from Arizona, Lots of organizing and engineering. January 7, 1999, first DIB spectra taken, 15 Mon and rho Leo. Signal to noise 500 in single spectra. The dream had come true. Technology, private telescope, lots of Vme, remote observing Since then, we have observed over 200 half nights, over 300 stars


Co authors: Julie Dahlstrom (Carthage) Dan Welty, Tak Oka, Lew Hobbs, Reid Sherman, Sean Johnson, Zihao Jiang (Chicago) Scoa Friedman, Paule Sonnentrucker (STScI) Brian Rachford (EmbryRiddle AeronauVcal University). Ted Snow (University of Colorado) arXiv:1305.3003


Multiple Spectrum Plot

Two reddened stars, S/N 3000 HD 183143
*
10 Lac HD204827

Beta Ori

Interstellar neutral sodium

* *
(

DIB 5780, 5797

5700A
Return to star choice menu
Redraw

5900A

Move wavelength window Redraw with plotting range: x = 5700 to 5900 y= 0 to 1.2
<<

>>

Include marks of known DIBs with offset


Two reddened stars, 54 DIBs in 200A

VerVcal Ticks: Red: HD 183143 Green: HD 204827 Black: Common DIBs

Return to star choice menu


The key to idenVficaVon lies in laboratory matching of spectra. (This has been tried since the Vme of Herzberg with no success.) ObservaVons of DIB profiles. This is what we can do. Two stories: a unique star in a nebula And the recent Supernova 2014J in M82


Herschel 36 in NGC 6530


Herschel 36 in NGC 6530, Dumbell Nebula, 33 APO spectra over 13 years.
1.02 Relative Flux 0.95 0.87 0.80 5777.0
Herschel36 HD 18326

1.02 Relative Flux 0.98 0.94 0.90 5795

*
5800 wavelength (е) 5805

5783.5 wavelength (е)

5790.0

1.01 Relative Flux 0.99 0.97 0.95 6194.0 6196.5 wavelength (е) 6199.0 Relative Flux

1.01 0.98 0.95 0.92 6611 6615 wavelength (е) 6619


IsolaVng the anomalous DIB Profiles to within 0.5 pc of Her 36

Distance from Her 36 1000 pc 10 pc 0.5 pc Herschel 36

IR pumping of J = 1 level of CH+ (not known anyplace else In ISM)



Herschel 36SE, 400 pc from Herschel 36, the infrared source that pumps rotaVonal levels of CH+ and DIBs


Supernova 2014J, M82, DIB profiles, stack of 47 spectra, 15 hours
LSR velocity, km/sec 100 0 +100 _+200 +300 200 LSR velocity, km/sec 0 400 200


Individual line profiles For SN2014J Welty (Chicago) Ritchey (UW) Dahlstrom (Carthage) York (Chicago)

Black trace--data Red trace--DIB proporVonal to K I Green trace­ x 7 weighVng for DIB in K I components.



FIN