200 likes | 368 Views
Science with ALMA Band 11 . Dimitra Rigopoulou (Oxford Univ. & RAL-Space, STFC) Oxford, March 19 & 20 th 2013. ALMA Band 11 : Why a THz Band. Originally ALMA to reach up to 950 GHz
E N D
Science with ALMA Band 11 Dimitra Rigopoulou (Oxford Univ. & RAL-Space, STFC) Oxford, March 19 & 20th 2013
ALMA Band 11 : Why a THz Band • Originally ALMA to reach up to 950 GHz • But results from ISO, APEX, Herschel & SOFIA highlight the tremendous scientific potential of observing in the THz bands Yes, above 30% transmission Is it feasible? Is it scientifically important?
Band 11: Sensitivities & Resolution Based on work carried out by S. Graves and J. Richer
High J CO transitions, H2 rotational transitions and fine structure lines redshift
Band 11 Science Drivers Very high redshift Universe: probe pristine gas in protogalaxies through detection of the pure rotational H2 lines 28 and 17 μm lines • H2 is the most abundant molecule in the Universe • Its whereabouts: • found in regions where shielding from UV • photons (responsible for its dissociation) is sufficiently large Av >=0.5-1mag • Key role: • H2 formation on grains initiates chemistry of ISM • Major contributor to the cooling of astrophysical media Devriendt& Slyz, using GALACTICA
Band 11 Science Drivers External Galaxies : Probe the properties of intermediate redshift 0.3<z<1 Universe [CII] @158 m (1.899 THz) in the redshift range 0.2-0.8 [NII] @ 205 m (1.950 THz) in the redshift range ~0.8 [OI] @ 63 m (4.758 THz) @ z~0.3 Magnelli et al. (2011))
Band 11 Science Drivers ELAIS-S1 z=0.27 Bootes1 z=0.35 A survey of [CII], [NII] and [OI] in intermediate redshift ULIRGs FLS01 z=0.46 Arp220 Rangwala et al. 2011
Band 11 Science Drivers Interstellar Medium of the Milky Way Probe PDRs via spatially resolved studies of [NII] and high-J CO High/low Excitation Lines of Fundamental Molecules HCN, HNC, HCO+ Higher J transitions of CO : e.g. CO(10-9), CO(11-10), CO(12-11) Hydrogen Fluorine @1232 GHz – tracer of H2, potential for detecting small H2 clouds Sonnentrucker, Neufeld et al AA, 521 Deduce HF/H2, calculate N(HF) Infer N(H2)
Band 11 Science Drivers High Mass Star Formation : SFR in galaxies traced via massive stars. Also responsible for the buildup of chemical elements, origins of planets and Life • high-J transitions of CO HCN, HNC and HCO+ Para-D2H+ Low mass star Formation: fundamental rotational transitions of NH+: N2H+, NH3 Para-NH3 (2-1) multiplet 1214.85 and 1215.24 GHz, chemistry of N H2D+ : ortho H2D+ @373 GHz BUTpara H2D+ @ 1370 GHz dominant form of H2D+, probe mid-plane of protostellar disks Search for o-D2H+ In 16293E Upper limit for o=-D2H+ Ortho-D2H+ Vastel et al, from the CHESS program
Band 11 Science Drivers Continuum imaging
Band 11 Science Drivers Studies of the continuum at 200-300 microns @ z 3-5 (essesntial for constraining AGN)
Band 11 Science Drivers: Synergies & complementarities B11 B11 from E. Bergin 11 1400 From ALMA-NRAO
Para-D2H+ Ortho-D2H+
Band 11 Science Drivers: Spectral Lines Unique Lines: fundamental rotational transitions of NH+: N2H+, NH3 Para-NH3 (2-1) multiplet 1214.85 and 1215.24 GHz, chemistry of N H2D+ : ortho H2D+ @373 GHz BUTparaH2D+ @ 1370 GHz dominant form of H2D+, probe mid-plane of protostellar disks High Excitation Lines of Fundamental Molecules HCN, HNC, HCO+ Higher J transitions of CO : e.g. CO(10-9), CO(11-10), CO(12-11) etc
Band 11 Science Drivers: Spectral Lines Unique Lines: fundamental rotational transitions of NH+: N2H+, NH3 Para-NH3 (2-1) multiplet 1214.85 and 1215.24 GHz, chemistry of N H2D+ : ortho H2D+ @373 GHz BUTparaH2D+ @ 1370 GHz dominant form of H2D+, probe mid-plane of protostellar disks High Excitation Lines of Fundamental Molecules HCN, HNC, HCO+ Higher J transitions of CO : e.g. CO(10-9), CO(11-10), CO(12-11) etc
Band 11 Science Drivers: Spectral Lines Unique Lines: fundamental rotational transitions of NH+: N2H+, NH3 Para-NH3 (2-1) multiplet 1214.85 and 1215.24 GHz, chemistry of N H2D+ : ortho H2D+ @373 GHz BUTparaH2D+ @ 1370 GHz dominant form of H2D+, probe mid-plane of protostellar disks High Excitation Lines of Fundamental Molecules HCN, HNC, HCO+ Higher J transitions of CO : e.g. CO(10-9), CO(11-10), CO(12-11) etc
Band 11 Science Drivers: Spectral Lines Unique Lines: fundamental rotational transitions of NH+: N2H+, NH3 Para-NH3 (2-1) multiplet 1214.85 and 1215.24 GHz, chemistry of N H2D+ : ortho H2D+ @373 GHz BUTparaH2D+ @ 1370 GHz dominant form of H2D+, probe mid-plane of protostellar disks D2H+ High Excitation Lines of Fundamental Molecules HCN, HNC, HCO+ Higher J transitions of CO : e.g. CO(10-9), CO(11-10), CO(12-11) etc