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This methodological paper describes the integration of the ‘European Health Interview Survey wave 2’ (EHIS 2) into the ‘German Health Update’ 2014/2015 (GEDA 2014/2015-EHIS). GEDA 2014/2015-EHIS is a cross-sectional health survey. A two-stage stratified cluster sampling approach was used to recruit persons aged 15 years and older with permanent residence in Germany. Two different modes of data collection were used, self-administered web questionnaire and self-administered paper questionnaire. The survey instrument implemented the EHIS 2 modules on health status, health care use, health determinants and social background variables and additional national questions. Data processing was conducted according to the quality and validation rules specified by Eurostat. In total, 24,824 questionnaires were completed. The response rate was 27.6%. The two-stage cluster sample method seems to have been successful in achieving a sample with high representativeness. The final micro data file was inspected, approved and certified by Eurostat. Access to micro data of the EHIS 2 can be provided by Eurostat via research contract and to the GEDA 2014/2015-EHIS public use file by the Research Data Centre of the Robert Koch Institute. First EHIS 2 results are available at the Eurostat website. Integrating a multinational health survey into an existing national health monitoring system was a challenge in Germany. The national survey methodology for conducting the survey had to be further developed in order to meet the overarching goal of harmonizing the health information from national statistical offices and public health research institutes across the European Union. The harmonized EHIS 2 data source will profoundly impact international public health research in the near future. The next EHIS wave 3 will be conducted around 2019.

Astronomical images from optical photometric surveys are typically contaminated with transient artifacts such as cosmic rays, satellite trails and scattered light. We have developed and tested an algorithm that removes these artifacts using a deep, artifact free, static sky coadd image built up through the median combination of point spread function (PSF) homogenized, overlapping single epoch images. Transient artifacts are detected and masked in each single epoch image through comparison with an artifact free, PSF-matched simulated image that is constructed using the PSF-corrected, model fitting catalog from the artifact free coadd image together with the position variable PSF model of the single epoch image. This approach works well not only for cleaning single epoch images with worse seeing than the PSF homogenized coadd, but also the traditionally much more challenging problem of cleaning single epoch images with better seeing. In addition to masking transient artifacts, we have developed an interpolation approach that uses the local PSF and performs well in removing artifacts whose widths are smaller than the PSF full width at half maximum, including cosmic rays, the peaks of saturated stars and bleed trails. We have tested this algorithm on Dark Energy Survey Science Verification data and present performance metrics. More generally, our algorithm can be applied to any survey which images the same part of the sky multiple times.

By using an internal part of the dnaK gene from Bacillus megaterium as a probe, a 5.2-kb HindIII fragment of chromosomal DNA of Bacillus subtilis was cloned. Downstream sequences were isolated by in vivo chromosome walking. Sequencing of 5,085 bp revealed four open reading frames in the order orf39-grpE-dnaK-dnaJ. orf39 encodes a 39-kDa polypeptide of unknown biological function with no noticeable homology to any other protein within the data bases. Alignment of the GrpE protein with those of three other bacterial species revealed a low overall homology, but a higher homology restricted to two regions which might be involved in interactions with other proteins. Alignment of the DnaK protein with six bacterial DnaK polypeptides revealed that a contiguous region of 24 amino acids is absent from the DnaK proteins of all known gram-positive species. Primer extension studies revealed three potential transcription start sites, two preceding orf39 (S1 and S2) and a third one in front of grpE (S3). S2 and S3 were activated at a high temperature. Northern (RNA) analysis led to the detection of three mRNA species of 4.9, 2.6, and 1.5 kb. RNA dot blot experiments revealed an at-least-fivefold increase in the amount of specific mRNA from 0 to 5 min postinduction and then a rapid decrease. A transcriptional fusion between dnaK and the amyL reporter gene exhibited a slight increase in alpha-amylase activity after heat induction. A 9-bp inverted repeat was detected in front of the coding region of orf39. This inverted repeat is present in a number of other heat shock operons in other microorganisms ranging from cyanobacteria to mycobacteria. The biological property of this inverted repeat as a putative key element in the induction of heat shock genes is discussed. The dnaK locus was mapped at about 223 degrees on the B. subtilis genetic map.

We use deep 70, 100 and 160 μm observations taken with PACS, the Photodetector Array Camera and Spectrometer on board of Herschel, as part of the PACS Evolutionary Probe (PEP) guaranteed time, to study the relation between star formation rate and environment at redshift  ~ 1 in the GOODS-S and GOODS-N fields. We use the SDSS spectroscopic catalog to build the local analog and study the evolution of the star formation activity dependence on the environment. At z~ 1 we observe a reversal of the relation between star formation rate and local density, confirming the results based on Spitzer 24 μm data. However, due to the high accuracy provided by PACS in measuring the star formation rate also for AGN hosts, we identify in this class of objects the cause for the reversal of the density–SFR relation. Indeed, AGN hosts favor high stellar masses, dense regions and high star formation rates. Without the AGN contribution the relation flattens consistently with respect to the local analog in the same range of star formation rates. As in the local universe, the specific star formation rate anti-correlates with the density. This is due to mass segregation both at high and low redshift. The contribution of AGN hosts does not affect this anti-correlation, since AGN hosts exhibit the same specific star formation rate as star forming galaxies at the same mass. The same global trends and AGN contribution is observed once the relations are studied per morphological type. We study the specific star formation rate vs. stellar mass relation in three density regimes. Our data provides an indication that at M/M⊙> 1011the mean specific star formation rate tends to be higher at higher density, while the opposite trend is observed in the local SDSS star forming sample.

Deep far-infrared photometric surveys studying galaxy evolution and the nature of the cosmic infrared background are a key strength of the Herschelmission. We describe the scientific motivation for the PACS Evolutionary Probe (PEP) guaranteed time key program and its role within the entire set of Herschelsurveys, and the field selection that includes popular multiwavelength fields such as GOODS, COSMOS, Lockman Hole, ECDFS, and EGS. We provide an account of the observing strategies and data reduction methods used. An overview of first science results illustrates the potential of PEP in providing calorimetric star formation rates for high-redshift galaxy populations, thus testing and superseding previous extrapolations from other wavelengths, and enabling a wide range of galaxy evolution studies.

Gravitational lensing by massive galaxy clusters allows study of the population of intrinsically faint infrared galaxies that lie below the sensitivity and confusion limits of current infrared and submillimeter telescopes. We present ultra-deep PACS 100 and 160 μm observations toward the cluster lens Abell 2218 to penetrate the Herschelconfusion limit. We derive source counts down to a flux density of 1 mJy at 100 μm and 2 mJy at 160 μm, aided by strong gravitational lensing. At these levels, source densities are 20 and 10 beams/source in the two bands, approaching source density confusion at 160 μm. The slope of the counts below the turnover of the Euclidean-normalized differential curve is constrained in both bands and is consistent with most of the recent backwards evolutionary models. By integrating number counts over the flux range accessed by Abell 2218 lensing (0.94–35 mJy at 100 μm and 1.47–35 mJy at 160 μm), we retrieve a cosmic infrared background surface brightness of ~8.0 and ~9.9 nW m-2sr-1, in the respective bands. These values correspond to 55±24% and 77±31% of DIRBE direct measurements. Combining Abell 2218 results with wider/shallower fields, these figures increase to 62±25% and 88±32% CIB total fractions, resolved at 100 and 160 μm, disregarding the high uncertainties of DIRBE absolute values.

Aims. We exploit deep observations of the GOODS-N field taken with PACS, the Photodetector Array Camera and Spectrometer, onboard of Herschel, as part of the PACS evolutionary probe guaranteed time (PEP), to study the link between star formation and stellar mass in galaxies to z~ 2.Methods. Starting from a stellar mass – selected sample of ~4500 galaxies with mag4.5 µm< 23.0 (AB), we identify ~350 objects with a PACS detection at 100 or 160 ~1500 with only Spitzer 24  μm counterpart. Stellar masses and total IR luminosities (LIR) are estimated by fitting the spectral energy distributions (SEDs). Results. Consistently with other Herschelresults, we find that LIRbased only on 24  μm data is overestimated by a median factor ~1.8 at z~ 2, whereas it is underestimated (with our approach) up to a factor ~1.6 at 0.5 < z< 1.0. We then exploit this calibration to correct LIRbased on the MIPS/Spitzerfluxes. These results clearly show how Herschelis fundamental to constrain LIR, and hence the star formation rate (SFR), of high redshift galaxies. Using the galaxies detected with PACS (and/or MIPS), we investigate the existence and evolution of the relations between the SFR, the specific star formation rate (SSFR=SFR/mass) and the stellar mass. Moreover, in order to avoid selection effects, we also repeat this study through a stacking analysis on the PACS images to fully exploit the far-IR information also for the Herscheland Spitzerundetected subsamples. We find that the SSFR-mass relation steepens with redshift, being almost flat at z< 1.0 and reaching a slope of α= -0.50+0.13-0.16at z~ 2, at odds with recent works based on radio-stacking analysis at the same redshift. The mean SSFR of galaxies increases with redshift, by a factor ~15for massive M> 1011$M_{\odot}$galaxies from z= 0 to z= 2, and seems to flatten at z> 1.5 in this mass range. Moreover, the most massive galaxies have the lowest SSFR at any z, implying that they have formed their stars earlier and more rapidly than their low mass counterparts (downsizing).

The star formation rate (SFR) is a key parameter in the study of galaxy evolution. The accuracy of SFR measurements at z~ 2 has been questioned following a disagreement between observations and theoretical models. The latter predict SFRs at this redshift that are typically a factor 4 or more lower than the measurements. We present star-formation rates based on calorimetric measurements of the far-infrared (FIR) luminosities for massive 1.5 < z< 2.5, normal star-forming galaxies (SFGs), which do not depend on extinction corrections and/or extrapolations of spectral energy distributions. The measurements are based on observations in GOODS-N with the Photodetector Array Camera and Spectrometer (PACS) onboard Herschel, as part of the PACS evolutionary probe (PEP) project, that resolve for the first time individual SFGs at these redshifts at FIR wavelengths. We compare FIR-based SFRs to the more commonly used 24 μm and UV SFRs. We find that SFRs from 24 μm alone are higher by a factor of ~4–7.5 than the true SFRs. This overestimation depends on luminosity: gradually increasing for log L(24 μm) > 12.2 $L_\odot$. The SFGs and AGNs tend to exhibit the same 24 μm excess. The UV SFRs are in closer agreement with the FIR-based SFRs. Using a Calzetti UV extinction correction results in a mean excess of up to 0.3 dex and a scatter of 0.35 dex from the FIR SFRs. The previous UV SFRs are thus confirmed and the mean excess, while narrowing the gap, is insufficient to explain the discrepancy between the observed SFRs and simulation predictions.

The constituents of the cosmic IR background (CIB) are studied at its peak wavelengths (100 and 160 μm) by exploiting Herschel/PACS observations of the GOODS-N, Lockman Hole, and COSMOS fields in the PACS evolutionary probe (PEP) guaranteed-time survey. The GOODS-N data reach 3σdepths of ~3.0 mJy at 100 μm and ~5.7 mJy at 160 μm. At these levels, source densities are 40 and 18 beams/source, respectively, thus hitting the confusion limit at 160 μm. Differential number counts extend from a few mJy up to 100-200 mJy, and are approximated as a double power law, with the break lying between 5 and 10 mJy. The available ancillary information allows us to split number counts into redshift bins. At z≤0.5 we isolate a class of luminous sources (LIR~ 1011$L_\odot$), whose SEDs resemble late-spiral galaxies, peaking at ~130 μm restframe and significantly colder than what is expected on the basis of pre-Herschelmodels. By integrating number counts over the whole covered flux range, we obtain a surface brightness of 6.36±1.67 and 6.58±1.62 [ nW m-2sr-1] at 100 and 160 μm, resolving ~45% and ~52% of the CIB, respectively. When stacking 24 μm sources, the inferred CIB lies within 1.1σand 0.5σfrom direct measurements in the two bands, and fractions increase to 50% and 75%. Most of this resolved CIB fraction was radiated at z≤1.0, with 160 μm sources found at higher redshift than 100 μm ones.

Sensitive Herschelfar-infrared observations can break degeneracies that were inherent to previous studies of star formation in high-zAGN hosts. Combining PACS 100 and 160 μm observations of the GOODS-N field with 2 Ms Chandradata, we detect ~20% of X-ray AGN individually at >3σ. The host far-infrared luminosity of AGN with $L_{2-10~{\rm keV}}$≈1043erg s-1increases with redshift by an order of magnitude from z = 0to z~ 1. In contrast, there is little dependence of far-infrared luminosity on AGN luminosity, for ${L_{2-10~{\rm keV}}}$$\la$1044erg s-1AGN at z$\ga$1. We do not find a dependence of far-infrared luminosity on X-ray obscuring column, for our sample which is dominated by $L_{2-10~{\rm keV}}$< 1044erg s-1AGN. In conjunction with properties of local and luminous high-zAGN, we interpret these results as reflecting the interplay between two paths of AGN/host coevolution. A correlation of AGN luminosity and host star formation is traced locally over a wide range of luminosities and also extends to luminous high-zAGN. This correlation reflects an evolutionary connection, likely via merging. For lower AGN luminosities, star formation is similar to that in non-active massive galaxies and shows little dependence on AGN luminosity. The level of this secular, non-merger driven star formation increasingly dominates over the correlation at increasing redshift.

The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60–210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60–85 μm or 85–125 μm and 125–210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47” × 47”, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions.

The constituents of the cosmic IR background (CIB) are studied at its peak wavelengths (100 and 160 μm) by exploiting Herschel/PACS observations of the GOODS-N, Lockman Hole, and COSMOS fields in the PACS evolutionary probe (PEP) guaranteed-time survey. The GOODS-N data reach 3σdepths of ~3.0 mJy at 100 μm and ~5.7 mJy at 160 μm. At these levels, source densities are 40 and 18 beams/source, respectively, thus hitting the confusion limit at 160 μm. Differential number counts extend from a few mJy up to 100-200 mJy, and are approximated as a double power law, with the break lying between 5 and 10 mJy. The available ancillary information allows us to split number counts into redshift bins. At z≤0.5 we isolate a class of luminous sources (LIR~ 1011$L_\odot$), whose SEDs resemble late-spiral galaxies, peaking at ~130 μm restframe and significantly colder than what is expected on the basis of pre-Herschelmodels. By integrating number counts over the whole covered flux range, we obtain a surface brightness of 6.36±1.67 and 6.58±1.62 [ nW m-2sr-1] at 100 and 160 μm, resolving ~45% and ~52% of the CIB, respectively. When stacking 24 μm sources, the inferred CIB lies within 1.1σand 0.5σfrom direct measurements in the two bands, and fractions increase to 50% and 75%. Most of this resolved CIB fraction was radiated at z≤1.0, with 160 μm sources found at higher redshift than 100 μm ones.

The star formation rate (SFR) is a key parameter in the study of galaxy evolution. The accuracy of SFR measurements at z~ 2 has been questioned following a disagreement between observations and theoretical models. The latter predict SFRs at this redshift that are typically a factor 4 or more lower than the measurements. We present star-formation rates based on calorimetric measurements of the far-infrared (FIR) luminosities for massive 1.5 < z< 2.5, normal star-forming galaxies (SFGs), which do not depend on extinction corrections and/or extrapolations of spectral energy distributions. The measurements are based on observations in GOODS-N with the Photodetector Array Camera and Spectrometer (PACS) onboard Herschel, as part of the PACS evolutionary probe (PEP) project, that resolve for the first time individual SFGs at these redshifts at FIR wavelengths. We compare FIR-based SFRs to the more commonly used 24 μm and UV SFRs. We find that SFRs from 24 μm alone are higher by a factor of ~4–7.5 than the true SFRs. This overestimation depends on luminosity: gradually increasing for log L(24 μm) > 12.2 $L_\odot$. The SFGs and AGNs tend to exhibit the same 24 μm excess. The UV SFRs are in closer agreement with the FIR-based SFRs. Using a Calzetti UV extinction correction results in a mean excess of up to 0.3 dex and a scatter of 0.35 dex from the FIR SFRs. The previous UV SFRs are thus confirmed and the mean excess, while narrowing the gap, is insufficient to explain the discrepancy between the observed SFRs and simulation predictions.

Sensitive Herschelfar-infrared observations can break degeneracies that were inherent to previous studies of star formation in high-zAGN hosts. Combining PACS 100 and 160 μm observations of the GOODS-N field with 2 Ms Chandradata, we detect ~20% of X-ray AGN individually at >3σ. The host far-infrared luminosity of AGN with $L_{2-10~{\rm keV}}$≈1043erg s-1increases with redshift by an order of magnitude from z = 0to z∼1. In contrast, there is little dependence of far-infrared luminosity on AGN luminosity, for ${L_{2-10~{\rm keV}}}$$\la$1044erg s-1AGN at z$\ga$1. We do not find a dependence of far-infrared luminosity on X-ray obscuring column, for our sample which is dominated by $L_{2-10~{\rm keV}}$< 1044erg s-1AGN. In conjunction with properties of local and luminous high-zAGN, we interpret these results as reflecting the interplay between two paths of AGN/host coevolution. A correlation of AGN luminosity and host star formation is traced locally over a wide range of luminosities and also extends to luminous high-zAGN. This correlation reflects an evolutionary connection, likely via merging. For lower AGN luminosities, star formation is similar to that in non-active massive galaxies and shows little dependence on AGN luminosity. The level of this secular, non-merger driven star formation increasingly dominates over the correlation at increasing redshift.

Aims. We exploit deep observations of the GOODS-N field taken with PACS, the Photodetector Array Camera and Spectrometer, onboard of Herschel, as part of the PACS evolutionary probe guaranteed time (PEP), to study the link between star formation and stellar mass in galaxies to z~ 2.

Gravitational lensing by massive galaxy clusters allows study of the population of intrinsically faint infrared galaxies that lie below the sensitivity and confusion limits of current infrared and submillimeter telescopes. We present ultra-deep PACS 100 and 160 μm observations toward the cluster lens Abell 2218 to penetrate the Herschelconfusion limit. We derive source counts down to a flux density of 1 mJy at 100 μm and 2 mJy at 160 μm, aided by strong gravitational lensing. At these levels, source densities are 20 and 10 beams/source in the two bands, approaching source density confusion at 160 μm. The slope of the counts below the turnover of the Euclidean-normalized differential curve is constrained in both bands and is consistent with most of the recent backwards evolutionary models. By integrating number counts over the flux range accessed by Abell 2218 lensing (0.94–35 mJy at 100 μm and 1.47–35 mJy at 160 μm), we retrieve a cosmic infrared background surface brightness of ~8.0 and ~9.9 nW m-2sr-1, in the respective bands. These values correspond to 55±24% and 77±31% of DIRBE direct measurements. Combining Abell 2218 results with wider/shallower fields, these figures increase to 62±25% and 88±32% CIB total fractions, resolved at 100 and 160 μm, disregarding the high uncertainties of DIRBE absolute values.

The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60–210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60–85 μm or 85–125 μm and 125–210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47” × 47”, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions.