We have observed 104 gravitationally-lensed quasars at $z\sim1-4$ with
Herschel/SPIRE, the largest such sample ever studied. By targeting
gravitational lenses, we probe intrinsic far-infrared (FIR) luminosities and
star formation rates (SFRs) more typical of the population than the extremely
luminous sources that are otherwise accessible. We detect 72 objects with
Herschel/SPIRE and find 66 percent (69 sources) of the sample have spectral
energy distributions (SEDs) characteristic of dust emission. For 53 objects
with sufficiently constrained SEDs, we find a median effective dust temperature
of $38^{+12}_{-5}$ K. By applying the radio-infrared correlation, we find no
evidence for an FIR excess which is consistent with star-formation-heated dust.
We derive a median magnification-corrected FIR luminosity of
$3.6^{+4.8}_{-2.4}~\times 10^{11}~{\rm L_{\odot}}$ and median SFR of
$120^{+160}_{-80}~{\rm M_{\odot}~yr^{-1}}$ for 94 quasars with redshifts. We
find $\sim10$ percent of our sample have FIR properties similar to typical
dusty star-forming galaxies at $z\sim2-3$ and a range of SFRs $<20-10000~{\rm
M_{\odot}~yr^{-1}}$ for our sample as a whole. These results are in line with
current models of quasar evolution and suggests a coexistence of dust-obscured
star formation and AGN activity is typical of most quasars. We do not find a
statistically-significant difference in the FIR luminosities of quasars in our
sample with a radio excess relative to the radio-infrared correlation.
Synchrotron emission is found to dominate at FIR wavelengths for $<15$ percent
of those sources classified as powerful radio galaxies.

通过观察具有引力透镜效应的类星体，探测到它们的远红外光度和星际成分，进而确定了射电和远红外之间的关联，揭示了星际尘埃中暗藏的恒星形成活动和 AGN 的共存现象，并没有发现与它们的射电属性相关的差异性。

引力透镜揭示类星体宿主星系中极端遮蔽星形成

Gravitational lensing reveals extreme dust-obscured star formation in  quasar host galaxies

(shortened) In this contribution an average or Galactic-field IMF is defined,
stressing that there is evidence for a change in the power-law index at only
two masses: near 0.5 Msun and 0.08 Msun. Using this supposed universal IMF, the
uncertainty inherent to any observational estimate of the IMF is investigated,
by studying the scatter introduced by Poisson noise and the dynamical evolution
of star clusters. It is found that this apparent scatter reproduces quite well
the observed scatter in power-law index determinations, thus defining the
fundamental limit within which any true variation becomes undetectable.
Determinations of the power-law indices alpha are subject to systematic errors
arising mostly from unresolved binaries. The systematic bias is quantified
here, with the result that the single-star IMFs for young star-clusters are
systematically steeper by d_alpha=0.5 between 0.1 and 1 Msun than the
Galactic-field IMF, which is populated by, on average, about 5 Gyr old stars.
The MFs in globular clusters appear to be, on average, systematically flatter
than the Galactic-field IMF, and the recent detection of ancient white-dwarf
candidates in the Galactic halo and absence of associated low-mass stars
suggests a radically different IMF for this ancient population. Star-formation
in higher-metallicity environments thus appears to produce relatively more
low-mass stars.

通过研究星团中泊松噪声和动力学演化引入的散射，确定了任何真正变化变得不可检测的范围，发现单星 IMFs 比银河星场 IMF 在 0.1 到 1Msun 之间陡峭，并发现更高金属丰度环境中的星际物质似乎会产生相对更多低质量的恒星。