Submillimeter Suborbital Missions: History and Prospects. Gordon Stacey Cornell University

Transcription

1 Submillimeter Suborbital Missions: History and Prospects Gordon Stacey Cornell University 1

2 First Observations NASA Lear Jet Observatory 30 cm telescope 2

3 Rich paper (1) First use of stressed Ge:Ga detectors for astronomical spectroscopy 3

4 Rich paper (2) First use of stressed Ge:Ga detectors for astronomical spectroscopy Line is brighter than expected line is coming from dense neutral gas not standard atomic clouds First estimates of fraction from ionized gas ~ 3 to 10% -- very modest since n e ~ 2000 cm -3 4

5 Rich paper (3) First use of stressed Ge:Ga detectors for astronomical spectroscopy Line is brighter than expected line is coming from dense neutral gas not standard atomic clouds First estimates of fraction from ionized gas ~ 3 to 10% Saturation of [CII] column, since it is determined by dust lower [CII]/FIR as FUV field goes up 5

6 Rich paper (4) First use of stressed Ge:Ga detectors for astronomical spectroscopy Line is brighter than expected line is coming from dense neutral gas not standard atomic clouds First estimates of fraction from ionized gas ~ 3 to 10% Saturation of [CII] column, since it is determined by dust lower [CII]/FIR as FUV field goes up Optical depth effects can be important 6

7 Rich paper (5) First use of stressed Ge:Ga detectors for astronomical spectroscopy Line is brighter than expected line is coming from dense neutral gas not standard atomic clouds First estimates of fraction from ionized gas ~ 3 to 10% Saturation of [CII] column, since it is determined by dust lower [CII]/FIR as FUV field goes up Optical depth effects can be important Use the [OI] line to constrain gas temperature (pressure) 7

8 Was apparent at first detection of [OI] 146 µm line that 63 µm line was optically thick Also apparent was importance of resonant scattering 8

9 Lear Jet Galactic Plane Observations Measured the scale height of the [CII] emission in inner galaxy arises from surfaces of molecular clouds, not ionized gas Termed [CII] regions L [CII] ~ L, or 0.3% of L FIR 10% arises in ELD ionized gas Stacey et al

10 KAO Days 1974 NASA Kuiper Airborne Observatory (KAO) 91-cm telescope 1975 until 1996 (shut down in prep for SOFIA) 10

11 1975 Figure EK. ESA Alan Moorwood, Jean Paul Baluteau, John Beckman, Ezio Bussoletti, Michel Anderegg (European Space Agency), 1975, with Baluteau s high resolution far infrared Fourier Transform Spectrometer. Voted best looking research group, 1975

12 1980 Figure EP. KAO staffer Bruce Kelly and Thijs DeGraauw, (Netherlands Institute for Space Research, Gronigen), 1980, inspecting the installation of de Graauw s heterodyne receiver on the KAO telescope.

13 Figure S. Charles Townes, Reinhard Genzel (University of California at Berkeley), They are planning a mapping strategy for locating guide stars to be used on observations with Townes far-infrared Fabry Perot spectrometer. 1981

14 1984 Figure EO. Undergratuate student Chuck Fuller, Gordon Stacey, Paul Viscuso, and Martin Harwit (Cornell University), A number of KAO investigators provided undergraduate students from their institutions exposure to the airborne astronomy operation. Voted best looking research group, 1984

15 Extended Emission from GMCs Stutzki et al Stacey et al Clumpy structures Low FIV fields on surface [CII]/CO(1-0) is a factor of 3 smaller on GMC 15

16 Put a bunch of OMC s together, and you get NGC

17 Extragalactic Work First extra-galactic surveys confirm dense neutral gas origins for [CII] fit into the context of photodissociation region models of Tielens and Hollenbach (1985) PDR context well established not diffuse HII or atomic clouds explaining the observed [CII]/CO correlation and [CII]/FIR ratio (~0.3%) High [CII]/CO(1-0) ratio for starburst galaxies and galactic star formation regions, 3 lower ratio for quiescent molecular clouds Use of [CII]/FIR to get G, and φ (following Wolfire et al. 1990) 3-pixel stressed Ge:Ga array Stacey et al

18 [CII]/CO ratio a metalicity effect noticed very early on Maloney and Black, 1988 Stacey et al

19 FIFI: Dark Gas 25-pixel stressed Ge:Ga array Studies 30 Doradus, Poglitsch et al IC 10, Madden et al N160, N159, Israel et al. 1996

20 Put into PDR Context by Wolfire et al

21 ~1995 Voted best looking research group, 1995

22 Detection of Emission from the Atomic Medium NGC 6946 Madden et al

23 1995 Voted just plain best looking Figure ET. Sue Madden, a postdoctoral associate at NASA Ames, Here she is seen checking detector biases on the Ames Cryogenic Grating Spectrometer (CGS), just prior to opening the telescope cavity door early in a flight.

24 Multiline Observations: M82 KAO/CGS Lord et al Lines: [SIII], [SiII], [OIII], [OI], [NII], [CII], [CI] Overall Conclusions: Clumpy neutral ISM 50% PDRs, 50% MC cores PDRs: G 0 ~ 700, n~3000 cm -3 Ionized ISM Density: 200 cm -3 Mass 20% of neutral gas Volume filling factor: 10% Stellar Population: 3 to 5 Myr old instantaneous starburst 100 M cut-off 24

25 Balloon Ionized Carbon Explorer 1998 Japanese group had several successful balloon experiments that observed [CII] and/or [OI] beginning with Shibai et al mapp of inner galaxy (BIRT) Very wide field done with BICE (350 < l II = 25 ; b II < 3 ): beam ~ 15 Found extended [CII] with respect to both CO and the FIR diffuse component, either ionized gas or atomic ISM seen for the first time 25

26 ESA/ESTEC and University College, London Ballooning Anderegg et al Highly successful balloon-borne FTS used to detect and map FIR fine-structure lines First detection of the astrophysically important [NIII] 57.4 µm line Maps of star formation regions in [OI] and [OIII] Moorwood et al

27 PIROG-7 Balloon 60 cm aperture First detection of 557 GHz water line from ISM Tauber et al

28 The Present and Future [CII] Platforms 28

29 SOFIA 29

30 SOFIA SOFIA epoch has begun One receiver operational now that is capable of observing the [CII] line and [NII] 205 µm lines: GREAT Sensitivity competitive with HIFI, but: Much more efficient mapper since SOFIA is a fast telescope Large throw, flexible positioning chopper allows for more sophisticated observing modes such as chopped on-the-fly mapping Modularity allows for continuing upgrades 30

31 GREAT, L#1 & L#2 channels GREAT - the Consortium PI-Instrument funded and developed by MPI Radioastronomie (2.7 THz channel) R. Güsten (PI) S. Heyminck (system engineer) B. Klein (FFT spectrometer) I. Camara, T. Klein (2.7 THz LO) Univ. zu Köln, KOSMA (1.4/1.9THz Voted best looking research group, 2012 but competition was FORCAST group :( channels) J. Stutzki (Co-PI) U. Graf (1.4 &1.9THz LO, Optics) K. Jacobs (HEB mixers up to 2.7 THz) R. Schieder (array-aos) DLR Planetenforschung (4.7 THz channel) H-W. Hübers (Co-PI: 4.7 THz HEB, IF, cal unit) MPI Sonnensystemforschung P. Hartogh et al. (CO-PI: CTS)

32 GREAT & upgreat

33 upgreat arrays

34 upgreat arrays factor ~10-20 improved mapping speed is expected (courtesy of C. Risacher, MPIfR)

35 > 20 GREAT Papers Okada, Y et al Dynamics and photodissociation region properties in IC 1396A Simon, R. et al SOFIA observations of S106: dynamics of the warm gas Perez-Beaupuits, J.P. et al The ionized and hot gas in M17 SW. SOFIA/GREAT THz observations of [C II] and 12 CO J = Sandell, G. et al GREAT [CII] and CO observations of the BD region Graf, U.U. et al. 2012, [ 12 CII] and [ 13 CII] 158 μm emission from NGC 2024: Large column densities of ionized carbon Mookerjea, B. et al. 2012, The structure of hot gas in Cepheus B Schneider, N. et al. 2012, Globules and pillars seen in the [CII] 158 μm line with SOFIA Sahai, R. et al. 2012, Probing the mass and structure of the Ring Nebula in Lyra with SOFIA/GREAT observations of the [CII] 158 micron line Rollig, et al. 2012, [CII] gas in IC

36 Hyperfine-structure in [ 13 CII] Line Graf et al Clear evidence for self-absorbed 12 [CII] emission Anomalous hyperfine line ratios 36

37 FIFI-LS A. Krabbe, A. Poglitsch, W. Raab, N. Geis, L. Looney, R. Honle, K. Nishikida, Th. Heening, E.E. Haller, and R. Klein Integral field (5 5 spatial) spectrometer (16 spectral) with two independent, simultaneous bands Blue: (6 pixels) Red: (12 pixels) Resolving power ~ 1000 to 3000 Slides from webavailable presentation of R. Klein 37

38 25 16 pixels stressed Ge:Ga Arrays 38

39 39

40 40

41 Comparision with PACS PACS is inherently 8 times more sensitive than FIFI- LS Shortest PACS observing block is 7 minutes long, for which the 1σ line noise is W/m 2 FIFI-LS/SOFIA is more versatile, and can have shorter integration times. Two minutes with FIFI-LS yields a noise ~ W/m 2 This is sufficient for mapping nearby galaxies in the FIR fine-structure lines PACS would take significantly longer (but produce much deeper imaging) FIFI-LS should be available on a shared risk basis within the next year, before transitioning to facility instrument status 41

42 High z Options: ZEUS-2 Four color, multiple beam system Simultaneous mapping in nearby galaxies in 5 lines Good sensitivity for high redshift systems: ~ W/m 2 on APEX Have obtained first light on APEX this past fall 42

43 CCAT Cornell, Caltech, University of Colorado, Cologne/Bonn, Canadian consortium, AUI, and NSF are developing CCAT 25 m submm telescope at the 5600 m summit of Cerro Chajnantor in Chile Gull

44 CCAT Scientific Inspiration Measure the star and characterize the history of star formation in galaxies through cosmic time Photometric surveys to resolve the FIR background Spectroscopic surveys characterizing the energy sources: stellar populations, shocks and AGN activity Probe the astrophysics of galaxy clusters through the Sunyaev-Zel dovich effect (S-Z) Characterize the star formation process locally through submm-wave spectroscopy and dust continuum emission Over 10 s of degree scales and through 5 orders of magnitude in scale for in the Milky Way Complete maps over a variety of environments in nearby resolved galaxies 44

45 CCAT Implementation Requirements: 25 meter telescope high surface accuracy (10 µm RMS goal) superb astronomical site: Cerro Chajnantor at 5617 m Highly accessible Wide (1 ) field of view 20 year lifetime Resolves the CIRB Beam ~λ(µm/100) ( ) Enables accurate astrometry for follow-up Can reach the confusion limit at 350 µm in a few hours Point source sensitivity comparable to ALMA in short submm bands: discovery and follow-up 45

46 CCAT Side Views 46

47 Looking Down on the ALMA Site 47

48 Why the Extra 600 Meters? Submillimeter sensitivity is all about telluric transmission Simon Radford has been running tipping radiometers at primary sites for more than a decade Simultaneous period for CCAT vs. ALMA site: median is 0.6 vs. 1.0 mm H 2 O factor of 1.4 in sensitivity Fraction of time Fraction of time 48

49 Median Conditions Median CCAT transmission even better than the pole due to warmer, less dense atmosphere Ω = 3 π, A med = 1.1 (z < 60 ) Pole: Ω = 1 π, A med = 1.4 (z < 60 ) 49

50 Top 10% Opens up the THz Windows Ω = 3 π, A med = 1.1 (z < 60 ) 50

51 Instrumentation Plans Four instruments are in preliminary design phase, all multi-institutional : Short Wavelength Camera (PI: G. Stacey, Cornell) (*) Long Wavelength Camera (PI: S. Golwala, Caltech) (*) Direct Detection MOS (PI: M. Bradford, JPL) (*) Heterodyne Feed Array (PI: J. Stützki, Kӧln) (*) Direct detection instruments MKIDs are technology of choice: they are intrinsically multiplexable, and can be implemented into large format arrays with relatively simple readout electronics. 432 pixel TiN MKID array for MAKO/SWCa m (Caltech/JPL) 51

52 Spectroscopy X-Spec: a very broad (50%) BW spectrometer [CII] much easier to detect Multiple CO lines help, and uniquely determine the redshift [CII] CO(6-5) [NII] CO(6-5) [CII] [CII] C. M. Bradford ALMA 5 to 10 times more sensitive per spectral tuning, but: Several tunings necessary CCAT spectrometer is multi-object Can be more efficient with CCAT spectrometer 52

53 CCAT Heterodyne Array Instrument (CHAI) Dual frequency band receiver covering frequencies around the carbon lines and CO(4-3), CO(7-6) 53

54 Simultaneous Mounting of Instruments 54

55 GUSSTO! Gal/Xgal U/LDB Spectroscopic/Stratospheric THz Observatory A Powerful, Unique Platform for SuperTHz Astronomy UofA/JHAPL/JPL/BATC/MIT/ASU/CIT/SRON/SAO/UMd/ KOSMA/UMass/Cornell/Oberlin/NRAO

56 [CII] and [OI] are the Most Luminous Lines in Galaxies representing ~1% of the total Far IR Luminosity Orion-KAO: (Borieko and Betz 1996) The GUSSTO [CII] & [NII] surveys: ~500x the angular resolution ~1000x the velocity resolution of COBE GUSSTO will perform the First Galaxy-wide survey of [OI], providing new insights into the energetics, dynamics, and chemistry of high mass star forming regions. GUSSTO [CII], [NII] & [OI] surveys of the LMC and nearby starburst galaxies complement the targeted observations made with the larger apertures of Herschel and SOFIA. 56

57 STO Galactic Plane Visibility GPS: Galactic Plane Survey: -20 o > l > -55 o ; -0.5 o < b < 0.5 o DS: Deep Survey of arm and interarm regions: l ~ -50 o and l ~ -40 o in b. MIPSGAL 24μm

58 GUSSTO Galactic Plane Visibility LDB ~45 Days ULDB ~100 Days +45 1st 4th 1st 4th 2nd 3rd nd Antarctic Launch/Recovery Antarctic Launch/New Zealand Recovery Why is GUSSTO coverage so much better than STO? Composite telescope alleviates Sun avoidance. New Gondola designed to look at higher elevations. Array Receivers allow larger regions to be surveyed in a given amount of time. Longer flight times 100 day flight makes more of the sky available. 3rd

59 Herschel: GOTC+ (Langer et al.) ~500 LOS of [CII] in Galactic Plane Traces HI clouds, interfaces with dense clouds and dark gas (with H in H 2 but with C not in CO) No [OI] or [NII] observations. 59

60 GUSSTO Mission Three 16 pixel heterodyne arrays simultaneous provide observations of [CII], [OI], and [NII] with >300 km/s velocity < 1km/s velocity resolution In 2 x ~45 day missions or one ~100 day mission, GUSSTO will observe ~100,000 LOS to a sensitivity level of ~0.2 K rms not possible with Herschel or SOFIA Should detect [CII] everywhere, [OI]/[NII] in higher excitation regions From Got C+ data, expect ~5 GMC s along a given LOS. 1 out of 6 LOS expected to intersect an [OI] emitting cloud. >10,000 [OI] detections expected toward GMCs in GUSSTO survey. Currently, only a handful of such high resolution [OI] spectra exist. Can potentially search for diffuse [OI] emission with GUSSTO through a combination of deep integrations and spatial convolution GUSSTO observations will play a key role in constructing an accurate Milky Way template for comparison to external 60 galaxies

61 Stratospheric TeraHertz Observatory (STO): Ideal Pathfinder for GUSSTO January 15, 2012 Balloon Parachute STO

62 STO [CII] Spectrum eta Carina optical image STO wide-field star camera image 1 50 " 7 STO [CII] spectrum of eta Carina at 1.9 THz (20 sec)

63 Conclusions Sub-orbital options still available, but not as sensitive as Herschel in the FIR Survey instruments attractive especially heterodyne were velocity information is used to detangle sources of emission High redshift universe studies very well enabled by future instrumentation I didn t even mention ALMA 63