The interstellar medium in high-redshift submillimeter galaxies as probed by infrared spectroscopy

Astrophysical Journal IOP Publishing 837:12 (2017)

Authors:

JL Wardlow, A Cooray, W Osage, N Bourne, D Clements, H Dannerbauer, L Dunne, S Dye, S Eales, D Farrah, C Furlanetto, E Ibar, R Ivison, S Maddox, MM Michałowski, D Riechers, Dimitra Rigopoulou, D Scott, MWL Smith, L Wang, PVD Werf, E Valiante, I Valtchanov, Aprajita Verma

Abstract:

Submillimeter galaxies (SMGs) at $z\gtrsim1$ are luminous in the far-infrared and have star-formation rates, SFR, of hundreds to thousands of solar masses per year. However, it is unclear whether they are true analogs of local ULIRGs or whether the mode of their star formation is more similar to that in local disk galaxies. We target these questions by using Herschel-PACS to examine the conditions in the interstellar medium (ISM) in far-infrared luminous SMGs at z~1-4. We present 70-160 micron photometry and spectroscopy of the [OIV]26 micron, [FeII]26 micron, [SIII]33 micron, [SiII]34 micron, [OIII]52 micron, [NIII]57 micron, and [OI]63 micron fine-structure lines and the S(0) and S(1) hydrogen rotational lines in 13 lensed SMGs identified by their brightness in early Herschel data. Most of the 13 targets are not individually spectroscopically detected and we instead focus on stacking these spectra with observations of an additional 32 SMGs from the \herschel\ archive -- representing a complete compilation of PACS spectroscopy of SMGs. We detect [OI]63 micron, [SiII]34 micron, and [NIII]57 micron at >3sigma in the stacked spectra, determining that the average strengths of these lines relative to the far-IR continuum are $(0.36\pm0.12)\times10^{-3}$, $(0.84\pm0.17)\times10^{-3}$, and $(0.27\pm0.10)\times10^{-3}$, respectively. Using the [OIII]52/[NIII]57 emission line ratio we show that SMGs have average gas-phase metallicities $\gtrsim Z_{\rm sun}$. By using PDR modelling and combining the new spectral measurements with integrated far-infrared fluxes and existing [CII]158 micron data we show that SMGs have average gas densities, n, of $\sim10^{1-3}{\rm cm^{-3}}$ and FUV field strengths, $G_0\sim10^{2.2-4.5}$ (in Habing units: $1.6\times10^{-3}{\rm erg~cm^{-2}~s^{-1}}$), consistent with both local ULIRGs and lower luminosity star-forming galaxies.

The $f(R)$ halo mass function in the cosmic web

(2017)

Authors:

Francesca von Braun-Bates, Hans A Winther, David Alonso, Julien Devriendt

The most massive galaxies in clusters are already fully grown at z similar to 0.5

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 465:2 (2017) 2101-2119

Authors:

LJ Oldham, RCW Houghton, RL Davies

Type Ibn Supernovae Show Photometric Homogeneity and Spectral Diversity at Maximum Light

The Astrophysical Journal American Astronomical Society 836:2 (2017) 158

Authors:

Griffin Hosseinzadeh, Iair Arcavi, Stefano Valenti, Curtis McCully, D Andrew Howell, Joel Johansson, Jesper Sollerman, Andrea Pastorello, Stefano Benetti, Yi Cao, S Bradley Cenko, Kelsey I Clubb, Alessandra Corsi, Gina Duggan, Nancy Elias-Rosa, Alexei V Filippenko, Ori D Fox, Christoffer Fremling, Assaf Horesh, Emir Karamehmetoglu, Mansi Kasliwal, GH Marion, Eran Ofek, David Sand, Francesco Taddia, WeiKang Zheng, Morgan Fraser, Avishay Gal-Yam, Cosimo Inserra, Russ Laher, Frank Masci, Umaa Rebbapragada, Stephen Smartt, Ken W Smith, Mark Sullivan, Jason Surace, Przemek Woźniak

Radiation hardness studies of AMS HV-CMOS 350 nm prototype chip HVStripV1

Journal of Instrumentation IOP Publishing 12:02 (2017) P02010

Authors:

K Kanisauskas, A Affolder, K Arndt, R Bates, M Benoit, FD Bello, A Blue, D Bortoletto, M Buckland, C Buttar, P Caragiulo, D Das, J Dopke, A Dragone, F Ehrler, V Fadeyev, Z Galloway, H Grabas, IM Gregor, P Grenier, A Grillo, B Hiti, M Hoeferkamp, LBA Hommels, BT Huffman, Jaya John, C Kenney, J Kramberger, Z Liang, I Mandic, D Maneuski, F Martinez-Mckinney, S MacMahon, L Meng, M Mikuž, D Muenstermann, R Nickerson, I Peric, P Phillips, R Plackett, F Rubbo, J Segal, S Seidel, A Seiden, I Shipsey, W Song, M Staniztki, D Su, C Tamma, R Turchetta

Abstract:

CMOS active pixel sensors are being investigated for their potential use in the ATLAS inner tracker upgrade at the HL-LHC. The new inner tracker will have to handle a significant increase in luminosity while maintaining a sufficient signal-to-noise ratio and pulse shaping times. This paper focuses on the prototype chip "HVStripV1" (manufactured in the AMS HV-CMOS 350nm process) characterization before and after irradiation up to fluence levels expected for the strip region in the HL-LHC environment. The results indicate an increase of depletion region after irradiation for the same bias voltage by a factor of ≈2.4 and ≈2.8 for two active pixels on the test chip. There was also a notable increase in noise levels from 85 e− to 386 e− and from 75 e− to 277 e− for the corresponding pixels.