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Extragalactic H2O Maser
The SMA observed the first H2O maser at millimeter wavelengths (183 GHz) in the extragalactic source NGC 3079. Discovery of the maser in an AGN beyond the long-known 22 GHz transition opens the possibility of future position-resolved radiative transfer modeling of accretion disks and outflows on scales of < 1 pc from massive black holes (Humphreys et al. 2005).
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Figure 3: Filled color contours: Millimeter continuum image of NGC 3079 at 193 GHz observed with the SMA. The peak flux density is 27 mJy beam-1 with a 1σ rms of 2.5 mJy beam-1; the integrated continuum flux density is 53 mJy. Line contours: 183 GHz maser emission at 1017 km s-1 (optical, heliocentric). The peak maser flux density in the image is 0.39 Jy beam-1. Positive emission is shown as solid lines, and negative features as dashed contours. Contours are k x 2σ, where k = -1, 1, 2, 3, and 1σ = 56 mJy beam-1. The black cross marks the position of peak 22 GHz H2O maser emission at 956 km s-1: σ2000 = 10h01m57.802s ± 0.001s, δ2000 = 55°40'47.26" ± 0.01" (Kondratko et al. 2005). The black solid arrow indicates the position angles (P.A.'s; -10° east of north) of the parsec-scale 22 GHz H2O maser disk (Kondratko et al. 2005) and of the kiloparsec-scale CO disk (Koda et al. 2002). The black dotted arrow marks the direction of relativistic outflow, with the uncertainty depicted by bracketing solid lines of P.A. = 126° ± 5° (Trotter et al. 1998; Sawada-Satoh et al. 2000; Middelberg et al. 2004; Kondratko et al. 2005). The arc to the east denotes the opening angle of the kiloparsec-scale superbubble outflowing from the galactic nucleus (e.g., Cecil et al. 2002). The SMA synthesized beam has an FWHM of 5.9" x 3.4" (upper sideband) and 6.1" × 3.6" (lower sideband, shown top left), with a P.A. of 27° in both cases. (Humphreys et al. 2005) |
Extended SMA (eSMA)
The first interferometric observations with the eSMA, which is composed of the SMA, JCMT, and CSO, measured the redshifted C I line (z = 0.886) in absorption at 1.1 mm from the southwestern image of the lensed quasar PKS 1830-211 (Bottinelli et al. 2008). The angular resolution was 0.55 x 0.22 arcsec. No absorption was observed from the northeastern component at a separation of ~ 1 arcsec. This is the first time [C I] has been detected in this quasar, allowing the first direct determination of the relative abundances of [C I] relative to CO in the molecular clouds of a spiral galaxy at z > 0.1.
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SMA Research
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