| Title: |
HerMES: Spectral Energy Distributions of Submillimeter Galaxies at z >4 |
| Authors: |
Huang, J. -S., Rigopoulou, D., Magdis, G., Rowan-Robinson, M., Dai, Y., Bock, J. J., Burgarella, D., Chapman, S., Clements, D. L., Cooray, A., Farrah, D., Glenn, J., Oliver, S., Smith, A. J., Wang, L., Page, M., Riechers, D., Roseboom, I., Symeonidis, M., Fazio, G. G., Yun, M., Webb, T. M. A., Efstathiou, A. |
| Publication Year: |
2014 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics |
| More Details: |
We present a study of the infrared properties for a sample of seven spectroscopically confirmed submillimeter galaxies at $z>$4.0. By combining ground-based near-infrared, Spitzer IRAC and MIPS, Herschel SPIRE, and ground-based submillimeter/millimeter photometry, we construct their Spectral Energy Distributions (SED) and a composite model to fit the SEDs. The model includes a stellar emission component at $\lambda_{\rm rest} <$ 3.5$ \mu$m; a hot dust component peaking at $\lambda_{rest} \sim$ 5$\,\mu$m; and cold dust component which becomes significant for $\lambda_{\rm rest} >$ 50$\,\mu$m. Six objects in the sample are detected at 250 and 350$ \mu$m. The dust temperatures for the sources in this sample are in the range of 40$-$80 K, and their $L_{\rm FIR}$ $\sim$ 10$^{13}$ L$_{\odot}$ qualifies them as Hyper$-$Luminous Infrared Galaxies (HyperLIRGs). The mean FIR-radio index for this sample is around $< q > = 2.2$ indicating no radio excess in their radio emission. Most sources in the sample have 24$ \mu$m detections corresponding to a rest-frame 4.5$ \mu$m luminosity of Log$_{10}$(L$_{4.5}$ / L$_{\odot}$) = 11 $\sim$ 11.5. Their L$_{\rm 4.5}$/$L_{\rm FIR}$ ratios are very similar to those of starburst dominated submillimeter galaxies at $z \sim$ 2. The $L_{\rm CO}-L_{\rm FIR}$ relation for this sample is consistent with that determined for local ULIRGs and SMGs at $z \sim$ 2. We conclude that submillimeter galaxies at $z >$ 4 are hotter and more luminous in the FIR, but otherwise very similar to those at $z \sim$ 2. None of these sources show any sign of the strong QSO phase being triggered.
Comment: 49 pages, 15 figures. Submitted to ApJ |
| Document Type: |
Working Paper |
| DOI: |
10.1088/0004-637X/784/1/52 |
| Access URL: |
http://arxiv.org/abs/1401.6079 |
| Accession Number: |
edsarx.1401.6079 |
| Database: |
arXiv |
