We present spectroscopic follow-up observations of 70μm selected galaxies from the SWIRE XMMLSS and Lockman Hole fields. We have measured spectroscopic redshifts for 293 new sources down to a 70μm flux limit of 9mJy and R < 22. The redshift distribution peaks at z ~ 0.3 and has a high redshift tail out to z = 3.5. We perform emission line diagnostics for 91 sources where [OIII], Hβ, [NII], Hα and [SII] emission lines are available to determine their power source. We find in our sample 13 QSOs, 1 Seyfert II galaxy, 33 star forming galaxies, 30 composite galaxies, 5 LINERs and 21 ambiguous galaxies. We fit single temperature dust spectral energy distributions (SEDs) to 81 70μm sources with 160μm photometry to estimate dust temperatures and masses. Assuming the dust emissivity factor (β) as 1.5, we determine temperatures in the range ~ 20-60K and dust masses with a range of 10{^6}-10{^9} M{_\odot}. Plotting these objects in the luminosity-temperature diagram suggests that these objects have lower dust temperatures than local IR luminous galaxies. The Herschel Space Observatory will be crucial in understanding the nature of these sources and to accurately determining the shape of the Rayleigh-Jeans tail of the dust SED. We then model SEDs from optical to far-IR for each source using a set of galaxy and quasar templates in the optical and near-IR (NIR) and with a set of dust emission templates (cirrus, M82 starburst, Arp 220 starburst and AGN dust torus) in the mid-IR (MIR) to far-IR (FIR). The number of objects fit with each dust template are: 57 Arp 220, 127 M82, 9 cirrus, 1 AGN dust torus, 70 M82 and cirrus, 26 M82 and AGN dust torus and 3 Arp 220 and AGN dust torus. We determine the total IR luminosity (LIR) in range 10{^8}-10{^{15}} L{_\odot} by integrating the SED models from 8 to 1000μm.
We present new observational determination of the evolution of the rest-frame 70 and 160 micron and total infrared (TIR) galaxy luminosity functions (LFs) using 70 micron data from the Spitzer Wide-area Infrared Extragalactic Legacy Survey (SWIRE). The LFs were constructed for sources with spectroscopic redshifts only in the XMM-LSS and Lockman Hole fields from the SWIRE photometric redshift catalogue. The 70 micron and TIR LFs were constructed in the redshift range 0<z<1.2 and the 160 micron LF was constructed in the redshift range 0<z<0.5 using a parametric Bayesian and the vmax methods. We …
S-CANDELS: The Spitzer-Cosmic Assembly Near-Infrared Deep Extragalactic Survey. Survey Design, Photometry, and Deep IRAC Source Counts
斯皮策宇宙大会深近红外河外遗产调查（S-CANDELS; PI G。Fazio）是一个第8周期的探索计划，旨在探测非常高红移（z > 5）的星系。为了减轻宇宙变化的影响，并利用哈勃空间望远镜多周期财政计划CANDELS在多个波段的深度同延覆盖，S-CANDELS在五个相距甚远的河外区域进行：UKIDSS超深巡天、扩展钱德拉深场南、COSMOS、HST深场北和扩展格罗斯带。S-CANDELS建立在斯皮策扩展深度调查（SEDS）现有的这些领域的覆盖范围之上，将积分时间从12小时增加到总共50小时，但在较小的区域内，0.16平方度。额外的深度显著增加了微弱星等下的勘测完整性。本文介绍了S-CANDELS调查的设计、处理和公开提供的数据产品。我们目前的IRAC双波段3.6+4.5微米目录达到26.5 AB MAG的深度。深IRAC计数的大约135,000个星系检测的S-CANDELS是一致的模型的基础上已知的星系种群。比早期斯皮策/IRAC调查更深的深度增加并没有揭示离散源对弥漫的宇宙红外背景（CIB）的显着额外贡献。因此，它仍然是正确的，只有大约一半的估计CIB通量从COBE/DIRBE解决。
The Deep Extragalactic VIsible Legacy Survey (DEVILS) is an ongoing high-completeness, deep spectroscopic survey of $\sim$60,000 galaxies to Y$<$21.2 mag, over $\sim$6 deg2 in three well-studied deep extragalactic fields: D10 (COSMOS), D02 (XMM-LSS) and D03 (ECDFS). Numerous DEVILS projects all require consistent, uniformly-derived and state-of-the-art photometric data with which to measure galaxy properties. Existing photometric catalogues in these regions either use varied photometric measurement techniques for different facilities/wavelengths leading to inconsistencies, older imaging data a…
Using high-resolution Hubble Space Telescope imaging data, we perform a visual morphological classification of $\sim 36,000$ galaxies at $z < 1$ in the DEVILS/COSMOS region. As the main goal of this study, we derive the stellar mass function (SMF) and stellar mass density (SMD) sub-divided by morphological types. We find that visual morphological classification using optical imaging is increasingly difficult at $z > 1$ as the fraction of irregular galaxies and merger systems (when observed at rest-frame UV/blue wavelengths) dramatically increases. We determine that roughly two-thirds of the to…
Deep Spitzer observations of infrared-faint radio sources: high-redshift radio-loud AGN?
弱射电源（IFRSs）是一类罕见的物体，在无线电波长相对明亮，但在红外和光学波长非常微弱。在这里，我们提出了敏感的近红外观测这些来源的样本作为斯皮策河外代表性体积调查（SERVS）的一部分。几乎所有的IFRS在~ 1 μ $Jy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is $ S_{3.6μm} ~ 0.2 $ μ$ Jy或更低的水平下都未被检测到，给出了无线电-红外通量密度比的极值。将这些天体与已知的天体类别进行比较表明，大多数可能是高红移射电响亮星系，可能遭受重大的尘埃灭绝。
CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey - The Hubble Space Telescope Observations, Imaging Data Products and Mosaics
We present the evolution of the star-formation dispersion - stellar mass relation ($σ_{SFR}$-M$_{\star}$) in the DEVILS D10 region using new measurements derived using the ProSpect spectral energy distribution fitting code. We find that $σ_{SFR}$-M$_{\star}$ shows the characteristic 'U-shape' at intermediate stellar masses from 0.1<z<0.7 for a number of metrics, including using the deconvolved intrinsic dispersion. A physical interpretation of this relation is the combination of stochastic star-formation and stellar feedback causing large scatter at low stellar masses and AGN feedback causing …
Evidence for Infrared-Faint Radio Sources as z > 1 Radio-Loud AGN
暗射电源（英语：Inferred-Faint Radio Source，缩写IFRS）是在澳大利亚望远镜大区域巡天（英语：Australia Telescope Large Area Survey）中发现的一类射电源，在斯皮策广域河外红外线巡天（英语：Spitzer Wide-area Infrared Extragaltic）中没有可观测到的中红外线对应物。扩展后的Chandra Deep Field South现在有更深的斯皮策成像（3.6至70微米），来自一些传统的调查。我们报告了两个IFRS源在IRAC图像中的检测。另外两个IFRS的未检测允许我们限制源类型。对这些天体的SED的详细模拟表明，它们与高红移（z > 1）活动星系核相一致。
For a sample of star forming galaxies in the redshift interval 0.15$<$z$<$0.3, we study how both the relative strength of the AGN infra-red emission, compared to that due to the star formation (SF), and the numerical fraction of AGNs, change as a function of the total stellar mass of the hosting galaxy group (M$^{*}_{\mathrm{group}}$), between $10^{10.25}$ and $10^{11.9}$M$_{\odot}$. Using a multi-component SED fitting analysis, we separate the contribution of stars, AGN torus and star formation to the total emission at different wavelengths. This technique is applied to a new multi-wavelength…
A Two-Component Power Law Covering Nearly Four Orders of Magnitude in the Power Spectrum of Spitzer Far-Infrared Emission from the Large Magellanic Cloud
We present the first detailed analysis of three extragalactic fields (IRAC Dark Field, ELAIS-N1, ADF-S) observed by the infrared satellite, AKARI, using an optimised data analysis toolkit specifically for the processing of extragalactic point sources. The InfraRed Camera (IRC) on AKARI complements the Spitzer space telescope via its comprehensive coverage between 8-24 microns filling the gap between the Spitzer IRAC and MIPS instruments. Source counts in the AKARI bands at 3.2, 4.1, 7, 11, 15 and 18 microns are presented. At near-infrared wavelengths, our source counts are consistent with coun…
Doubly ionized silicon (SiIII) is a powerful tracer of diffuse ionized gas inside and outside of galaxies. It can be observed in the local Universe in ultraviolet (UV) absorption against bright extragalactic background sources. We here present an extensive study of intervening SiIII-selected absorbers and their relation to the circumgalactic medium (CGM) of galaxies at low redshift (z<=0.1), based on the analysis of UV absorption spectra along 303 extragalactic lines of sight obtained with the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST). Along a total redshift p…
The diffuse extragalactic background light (EBL) is formed by ultraviolet (UV), optical, and infrared (IR) photons mainly produced by star formation processes over the history of the Universe, and contains essential information about galaxy evolution and cosmology. Here, we present a new determination of the evolving EBL spectral energy distribution using a novel approach purely based on galaxy data aiming to reduce current uncertainties on the higher redshifts and IR intensities. Our calculations use multiwavelength observations from the UV to the far-IR of a sample of approximately 150,000 g…
