309 research outputs found
Dust correction factors over in massive star-forming galaxies from stacking in \emph{Herschel}
In this work we use stacking analysis in \emph{Herschel} PACS to study the
accuracy of several dust-correction factors typically employed to estimate
total star-formation rate (SFR) of high-redshift star-forming (SF) galaxies. We
also analyze what stacking suggests about the relation between SFR and stellar
mass and the redshift evolution of the specific SFR (). We find that the dust properties of massive SF galaxies evolve
with redshift, being galaxies at more attenuated than at for a given UV continuum slope and stellar mass. As a consequence, a single
IRX- relation can not be used to recover the total SFR of massive SF
galaxies at . This might have implications for higher
redshift studies, where a single IRX- relation derived for local
starburst is usually assumed to be valid. However, we find that the local
relation between dust attenuation and stellar mass is valid at least up to , although deviations are found for higher redshift galaxies where only
galaxies are detected
through stacking. This, therefore, does not rule out the possibility that the
local dust-mass relation can be valid for less massive SF galaxies at . The SED fitting procedure with stellar population templates gives
over-estimated values (about 0.3--0.5 dex in ) of the
dust-corrected SFR at all redshifts studied here. We find that the slope of the
main-sequence of star formation is less steep than previously found in massive
galaxies with , and the redshift
evolution of the sSFR reported in previous works in massive is well recovered.Comment: Accepted for publication in A&
Surveillance of a pest through a public health information system: The case of the blackfly (simulium erythrocephalum) in zaragoza (Spain) during 2009–2015
Background: Animals and people in many Spanish regions are increasingly being affected by blackfly bites in the last decade. Because of blackflies, the city of Zaragoza has become in recent years a paradigm of discomfort in Europe, with thousands of citizens affected. The OMI-AP system (Stacks, Barcelona, Spain) implemented by the Government of Aragón, a software that manages the electronic medical history of all patients, has been evaluated in order to document the increase of insect bite recorded by the primary care consultations in Zaragoza after the first outbreak of blackflies occurred in 2011.
Methods: An observational, ecological and longitudinal study of insect bites recorded at the primary care consultations was carried out in primary care during the period 2009–2015.
Results: The incidence of medical consultations by insect bites in Basic Health Areas (BHA) near to rivers is higher than the furthest BHA. Rural BHA are more affected by insect bites than the urban ones. The increase of medical assistance due to insect bites in Zaragoza since 2011 is correlated with the blackflies bites.
Conclusions: This tool was very useful to describe the initial stage of this public health problem. It could be used for guiding public health responses in terms of surveillance and management of this pest
A 1.4 deg^2 blind survey for C II], C III] and C IV at z ~ 0.7-1.5 - II. Luminosity functions and cosmic average line ratios
Article / Letter to editorSterrewach
Herschel Far-IR counterparts of SDSS galaxies: Analysis of commonly used Star Formation Rate estimates
We study a hundred of galaxies from the spectroscopic Sloan Digital Sky
Survey with individual detections in the Far-Infrared Herschel PACS bands (100
or 160 m) and in the GALEX Far-UltraViolet band up to z0.4 in the
COSMOS and Lockman Hole fields. The galaxies are divided into 4 spectral and 4
morphological types. For the star forming and unclassifiable galaxies we
calculate dust extinctions from the UV slope, the H/H ratio and
the ratio. There is a tight correlation between the
dust extinction and both and metallicity. We calculate
SFR and compare it with other SFR estimates (H, UV, SDSS)
finding a very good agreement between them with smaller dispersions than
typical SFR uncertainties. We study the effect of mass and metallicity, finding
that it is only significant at high masses for SFR. For the AGN and
composite galaxies we find a tight correlation between SFR and L
(0.29), while the dispersion in the SFR - L relation is
larger (0.57). The galaxies follow the prescriptions of the
Fundamental Plane in the M-Z-SFR space.Comment: 24 pages, 23 figures, accepted for publication in MNRA
Physical properties of Lyman-alpha emitters at from UV-to-FIR measurements
The analysis of the physical properties of low-redshift Ly emitters
(LAEs) can provide clues in the study of their high-redshift analogues. At , LAEs are bright enough to be detected over almost the entire
electromagnetic spectrum and it is possible to carry out a more precise and
complete study than at higher redshifts. In this study, we examine the UV and
IR emission, dust attenuation, SFR and morphology of a sample of 23
GALEX-discovered star-forming (SF) LAEs at with direct UV (GALEX),
optical (ACS) and FIR (PACS and MIPS) data. Using the same UV and IR limiting
luminosities, we find that LAEs at tend to be less dusty, have
slightly higher total SFRs, have bluer UV continuum slopes, and are much
smaller than other galaxies that do not exhibit Ly emission in their
spectrum (non-LAEs). These results suggest that at Ly
photons tend to escape from small galaxies with low dust attenuation. Regarding
their morphology, LAEs belong to Irr/merger classes, unlike non-LAEs. Size and
morphology represent the most noticeable difference between LAEs and non-LAEs
at . Furthermore, the comparison of our results with those obtained
at higher redshifts indicates that either the Ly technique picks up
different kind of galaxies at different redshifts or that the physical
properties of LAEs are evolving with redshift.Comment: Accepted for publication in Ap
- …