High Angular Resolution SMA Imaging of High Redshift Galaxies at 345 GHz

1. BR1202S BR1202N References: Borys, C. et al, 2006, ApJ, 636, 134 Giavalisco,M. et al, 2004, ApJ, 600, L93 Iono, D. et al, 2006, ApJ, 645, L97 Iono, D. et al, 2006, ApJ, 640, L1 Iono, D. et al, 2006b, PASJ, 58, 6 (in press) Jannuzi, B. & Dey, A., 1999, ASP 191, p111 Pope, A. et al, 2005, MNRAS, 358, 149 Acknowledgements: We would like to thank all the staff and postdocs at the SMA for their continued dedication and hard work that makes these observations possible. High Angular Resolution SMA Imaging of High Redshift Galaxies at 345 GHz Alison Peck (CfA), Daisuke Iono (NAOJ), Glen Petitpas (CfA) and the SMA Team CII at z=4.7 At left, we present a 3'' resolution 900 m continuum image and a detection of the redshifted CII line emission from the z=4.7 QSO BR 1202-0725 obtained using the SMA. The continuum image was made using line free channels in the lower sideband. The angular resolution in the continuum image is 3.4” x 2.7” and the RMS noise is 3 mJy. The insets above show the line profile toward the northern (BR1202N) and southern (BR1202S) components obtained at the peak pixels. The velocity resolution shown is 120 km s-1. The systemic velocity marked 0 km s -1 corresponds to 334 GHz. This is one of the first detections of the CII line from a high redshift source. The line is associated with the northern component, BR1202N. The low CII-FIR ratio of ~3.8 x 10-4 is similar to local ULIRGs. We have also found that X-ray emission is clearly detected from BR1202S, and at 99.6% confidence from BR1202N, suggesting that BR1202-0725 is the first example of a pair of AGN hosts at z~4.7. For more information, see Iono et al. 2006. Abstract Recent single-dish submillimeter wavelength surveys have revolutionized observational cosmology by uncovering a substantial new population of dust-enshrouded starburst galaxies at high redshift. A tremendous amount can be learned about the star formation history of the universe by comparing the characteristics of these early sources at a range of wavelengths, from radio to x-ray. Unfortunately, the positions of these sources are not well enough determined in the parent surveys to justify devoting large amounts of time using higher resolution instruments without first performing high precision astrometry. The Submillimeter Array on Mauna Kea is now the ideal instrument for this, as it can observe at the same frequency as the original survey, but with substantially better angular resolution, yielding astrometric accuracies of ~100 mas. We present images of the distant galaxies detected to date using the Submillimeter Array at 345 GHz. Earliest Results Subarcsecond Astrometry Right: APM08279+5255 is a well known lensed quasar with an 850 micron flux of ~50 mJy measured using SCUBA. This source was used as an initial feasibility target in 2003 before the detection of weaker high redshift sources was attempted. Though we only had 5 antennas and 600 MHz bandwidth at the time, the source was detected in 5 hours at nearly 5 sigma. The beam shown in the lower left corner of the image is 2x2.5 arcseconds. We plan to observe this source in the next few weeks in our Very Extended configuration to obtain sub-arcsecond resolution, which we hope will allow us to resolve the source and thus put constraints on the size of the lensed image(s). Below: The first panel shows the synthesized image of GN 20 made by adding 2 nights of SMA data (with astrometric verification source shown in the inset). The contours are 1,2,3... x RMS noise level of 2 mJy. The derived flux from a u,v fit is 23 +/- 3 mJy with a positional uncertainty of 0.15". The central panel shows the SMA contours overlaid on the deep Spitzer IRAC image. The third panel shows a smaller field with the SMA continuum contours on the HST ACS V-band image. Both images were obtained from the GOODS archive (Giavalisco et al 2004). GN20 was discovered in the recent SCUBA observations of the GOODS North Field with S/N close to 10 (Pope et al 2005). It is not detected in 450µm, radio, or in X-ray, but its robust SCUBA detection and a detection at 1.3 mm makes this one of the brightest sub-mm sources discovered to date. Most Recent Results Left: SXDF 850.6 is a source in the SCUBA Half Degree Extragalactic Survey (SHADES) which has multiple possible VLA radio and Subaru optical counterparts, but no established sub-mm source identification. The strongest radio emission has no confirmed optical counterpart, but the two secondary radio peaks both have apparent optical associations. These preliminary plots shows our most recent result. The source detected is consistent with the position of one of the marginal VLA detections. The peak flux in the top image is 6 mJy, making it the faintest high redshift source detected at the SMA thus far. The contours are 2,3,4… x RMS noise level of 1.4 mJy. Above: MIPS-J1428 was discovered to be the strongest source in the Spitzer MIPS images of the Bootes GTO field, with a flux of 240 mJy. This source has been observed spectroscopically at Keck, yielding a redshift z = 1.5. Subsequent SCUBA observations measured the flux of MIPS-J1428 to be >20 mJy at 850 µm. There is another galaxy 2.4'' away from the MIPS detection, but the low resolution radio map did not allow precise identification of the sub-mm emitting galaxy, despite its strong radio emission. More information about this source can be found in Iono et al. (2006) and Borys et al. (2006), and Iono et al. (2006b) also present recent CO(3-2) and CO(2-1) detections toward this source. The first panel shows the synthesized image of MIPS-J1428 made using 2 nights of SMA observing time (with astrometric verification source shown in the inset). The contours are 1,2,3… x RMS noise level of 2 mJy. The derived flux from a u,v fit is 18 +/- 3 mJy with a positional uncertainty of 0.1-0.2". The second and third panels show the SMA contours overlaid on the NDWFS (Jannuzi & Dey 1999) K- and I-band images, respectively. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy & Astrophysics