Science Prospects with the wsma
SMA: the key mm interferometry facility the SMA has genuinely transformed fields, from planet formation to the high-redshift universe 700 publications; 21000 citations (>1 paper/week; earn 5 cites/day!)
wsma: 16x wider instantaneous bandwidth continuum: 16x faster (4x deeper) spectral lines: 16x grasp (4x fewer settings)
wsma: practical scientific benefits every measurement is an imaging spectral line survey most efficient resolved spectral line mapping facility nimble, flexible, more sensitive for time domain studies (and everything we do now is better and faster)
wsma: practical observational benefits wide bandwidth improves image fidelity (multifrequency synthesis; Δν/ν~0.1-0.2) better sensitivity especially beneficial at longest baselines (leveraging SMA resolution) more robust phase transfer (nearby calibrators)
wsma complements ALMA ALMA pressure >7:1 you can t do it all (and the TAC knows it) wsma strengths: high-risk seed studies rapid response projects long-term, large surveys crucial mm VLBI station development (explicit)
some examples of key wsma science modes spatially resolved spectral line surveys (star formation, evolved stars, high-z galaxies) time domain / transient / ToO science (Sgr A* activity, comets, gamma-ray bursts) bonus or miscellaneous modes (mm VLBI / EHT, [CII] intensity mapping)
chemical evolution in star formation example: 24 GHz in 3 settings dramatic chemical changes precipitated by desorption wsma gets more than this in only one setting can map entire SF regions (inventory; seed projects; etc)
chemical evolution in star formation galactic scales too (starbursts/agn) 0 20 40 60 80 100 1 (a) Arp 220 CO(3-2) Dec. offset [arcsec] 0-1 -2 0.38" x 0.28" 300 pc 1 0-1 -2 R.A. offset [arcsec] 0 50 100 150 200 1 (d) Arp 220 0.86 mm Dec. offset [arcsec] 0-1 -2 N E 0.25" x 0.21" 300 pc 1 0-1 -2 R.A. offset [arcsec]
ISM enrichment from evolved stars mass-loss rates; wind physics chemistry > dust mineralogy example: 64 GHz (13 tracks) 1 wsma track
star formation in high redshift galaxies lensed starbursts; multi-line studies (CO, H2O, fine structure lines, etc; reservoirs and UV heating from star formation)
rement of the SgrA* Faraday rotation ( 5.6±0.7) 10 5 rad m 2, the accretion rate, 2 200 10 9 M yr 1 (Marrone et al., etry and (dis)order of the magnetic field. Previously, Faraday aring observations at different frequencies at different times. gra* is time variable in both intensity and polarization, the ere uncertain. Moreover, high angular resolution has proven ded (and also polarized) surroundings. ole is why gy radiaate, or alcooled by se adveche energy etion flow le leaving We hope ly enough r mystery m the X Are they velengths the sub- 0% polar- Figure 10: Light-curves of SgrA* in the submillimeter (SMA), infrared (Keck) and X-ray (Chandra), showing a flare with a timescale of order an hour (Marrone et al., 2015). The wsma will provide sufficient continuum sensitivity to detect such flares easily and to measure changes in polarization during the flare events. timescale ost powerful explosions in the universe and are observagh-energies the SMA (prompt emission) and long-lived afterglows pe verage in the is essential to fully characterize the energetics. he t and wsma can be observed with telescopes of modest aperurations, in Faraday and the rotation spectral inhardness SgrA*, and of prompt henceemission variations in the g-soft as the and flares. short-hard For example, GRBs. if the The flaring long GRBs is caused occur by a jet or hen ith the thedeaths Faraday of massive rotationstars; should these remain present constant a unique during the etion rst generation flow itself stars. through The short magnetic GRBs reconnection result from mergurces of gravitational waves. High cadence multi-band or an increase rotation should change with the flare. The wsma could cononitoring the activity of SgrA*, to characterize the variability the explosion physics. The submillimeter is especially sion associated with both types of GRBs. These events the submillimeter thanintheradio. SgrA* as well as nearby low luminosity active galactic nuclei r GRBs, a reverse relationship tes at long waveafterglowthis phase. relationship demonstrates that the emission in between the characteristic variability time scale, 2015). and 10measuring Schwarzschild its radii of the black hole. Blazars and radio nship. ant parameters Ongoingof monitoring of other low luminosity AGN will actor tionship andholds. magne- Monitoring of all these systems is critical for vations, for GRBs which have require detailed spectral modeling, as well as n the in most case cases, of flares a (see 5.1). t the typical synband. The wsma k emission in the d 1 to 10 minutes Figure 12: The spectral energy distribution of GRB120326A, 6.42 10 s of GRB120326A 15 4 time domain / transients Sgr A* simultaneous multi-freq Faraday measurements time variability of accretion rate (crucial for mm VLBI interpretations) comets separate coma and jet contributions (spatially and through spectral line ratios) short time variability of outgassing (in jets) gamma-ray burst afterglows reverse shock synchrotron emission; B-field, Γ requires very rapid ToO (~minutes) in principle, can see them at z~10 or more
other exciting wsma modes [CII] intensity mapping line emission from normal galaxies at high redshift (3.5-10) inferred statistically: fluctuations around mean line strength blind surveys over large volumes; robust cross-calibration millimeter VLBI (and EHT) imaging supermassive black holes at event horizon scales SWARM, etc. designed from ground up to do this well only long E-W baseline; reliable weather (non-imaging)
Science with the wideband Submillimeter Array: A Strategy for the Decade 2017 2027 ed. D. Wilner contributing authors: E. Keto, G. Bower, M. Gurwell, G. Keating, N. Patel, G. Petitpas, C. Qi, TK Sridharan, Y. Urata, K. Young, Q. Zhang, J.-H. Zhao Version 1.7, December 1, 2016 much more info in the wsma white paper! Figure 1: The eight 6-meter antennas of the Submillimeter Array on Maunakea, Hawaii (credit N. Patel).