Game species monitoring using road-based distance sampling in association with thermal imagers: a covariate analysis

Monitorización de especies cinegéticas utilizando el muestreo a distancia con base en una carretera, en combinación con imágenes termográficas: un análisis de covariables La monitorización de las poblaciones de especies cinegéticas es necesaria para evaluar adecuadamente las capturas de los cazadores, en zonas que carecen de los grandes depredadores naturales. Sin embargo, los gestores de la caza deben controlar diversas especies y a menudo carecen de un método de control con un diseño conveniente. Por lo tanto, la monitorización de diversas especies al mismo tiempo en áreas muy grandes podría ser eficaz desde el punto de vista de los costes y del tiempo. Estudiamos la influencia de diversos factores durante la monitorización de tres especies cinegéticas comunes (el jabalí, el corzo y el zorro rojo) utilizando un muestreo a distancia desde la carretera, en asociación con imágenes termográficas. Este examen piloto basado en 20 recuentos nocturnos en cinco lugares contrastantes estudió el efecto de diversas covariables (especie, termografía, observador, tamaño del grupo y tipo de hábitat) sobre las probabilidades de detección (dp). No se hallaron diferencias entre las imágenes termográficas (dpJENOPTIK: 0,186, dpFLIR: 0,193) y el tamaño de los grupos (dp1ind.: 0,243, dp2ind.: 0,259, dp> 2ind.: 0,223), pero sí entre los observadores (dpobs1: 0,207, dpobs2: 0,274, dpobs3: 0,159). También se observaron diferencias esperadas entre las especies (dpwild boar: 0,22, dproe deer: 0,35, dpred fox: 0,32) y entre los tipos de hábitat (dpforest: 0,27, dpedge: 0,74, dpopen: 0,35). Nuestros resultados demuestran que la detectabilidad de los equipos de termografía de bajo coste es similar a la de otros métodos caros, destacando nuevas posibilidades del uso de la termografía para los gestores de la caza. Aunque deberían realizarse ajustes en el diseño del estudio, nuestros hallazgos sugieren que la monitorización de múltiples especies a gran escala podría ser un método eficaz para las especies cinegéticas comunes.Monitorización de especies cinegéticas utilizando el muestreo a distancia con base en una carretera, en combinación con imágenes termográficas: un análisis de covariables La monitorización de las poblaciones de especies cinegéticas es necesaria para evaluar adecuadamente las capturas de los cazadores, en zonas que carecen de los grandes depredadores naturales. Sin embargo, los gestores de la caza deben controlar diversas especies y a menudo carecen de un método de control con un diseño conveniente. Por lo tanto, la monitorización de diversas especies al mismo tiempo en áreas muy grandes podría ser eficaz desde el punto de vista de los costes y del tiempo. Estudiamos la influencia de diversos factores durante la monitorización de tres especies cinegéticas comunes (el jabalí, el corzo y el zorro rojo) utilizando un muestreo a distancia desde la carretera, en asociación con imágenes termográficas. Este examen piloto basado en 20 recuentos nocturnos en cinco lugares contrastantes estudió el efecto de diversas covariables (especie, termografía, observador, tamaño del grupo y tipo de hábitat) sobre las probabilidades de detección (dp). No se hallaron diferencias entre las imágenes termográficas (dpJENOPTIK: 0,186, dpFLIR: 0,193) y el tamaño de los grupos (dp1ind.: 0,243, dp2ind.: 0,259, dp> 2ind.: 0,223), pero sí entre los observadores (dpobs1: 0,207, dpobs2: 0,274, dpobs3: 0,159). También se observaron diferencias esperadas entre las especies (dpwild boar: 0,22, dproe deer: 0,35, dpred fox: 0,32) y entre los tipos de hábitat (dpforest: 0,27, dpedge: 0,74, dpopen: 0,35). Nuestros resultados demuestran que la detectabilidad de los equipos de termografía de bajo coste es similar a la de otros métodos caros, destacando nuevas posibilidades del uso de la termografía para los gestores de la caza. Aunque deberían realizarse ajustes en el diseño del estudio, nuestros hallazgos sugieren que la monitorización de múltiples especies a gran escala podría ser un método eficaz para las especies cinegéticas comunes.Monitoring of game species populations is necessary to adequately assess culling by hunters in areas where natural large predators are absent. However, game managers have to control several species and they often lack of an efficient and convenient survey design method. Monitoring several species at that same time over large areas could thus be cost– and time–effective. We tested the influence of several factors during monitoring of three common game species, (wild boar, roe deer and red fox, using road–based distance sampling in association with thermal imagers. This pilot survey based on 20 night counts in five contrasting sites studied the effect of several covariates (species, thermal imaging, observer, group size, and habitat type) on the detection probabilities (= dp). No differences were observed between thermal imagers (dpJENOPTIK: 0.186, dpFLIR: 0.193) and group sizes (dp1ind.: 0.243, dp2ind.: 0.259, dp> 2ind.: 0.223), but we found differences between observers (dpobs1: 0.207, dpobs2: 0.274, dpobs3: 0.159). Expected differences were also observed between species (dpwild boar: 0.22, dproe deer: 0.35, dpred fox: 0.32) and between habitat type (dpforest: 0.27, dpedge: 0.74, dpopen: 0.35). Our results show that the detectability of low cost thermal imaging equipment is similar to that of more expensive methods, highlighting new possibilities for the use of thermal imagery by game managers. Although adjustments should be made to the study design our findings suggest that large–scale multi–species monitoring could be an efficient method for common game species

Constraint on the Assembly and Dynamics of Galaxies. II. Properties of Kiloparsec-Scale Clumps in Rest-Frame Optical Emission of z ~ 2 Star-Forming Galaxies

We study the properties of luminous stellar "clumps" identified in deep, high-resolution Hubble Space Telescope NIC2/F160W imaging at 1.6 μm of six z ~ 2 star-forming galaxies with existing near-infrared integral field spectroscopy from SINFONI at the Very Large Telescope. Individual clumps contribute ~0.5%-15% of the galaxy-integrated rest-frame ≈5000 Å emission, with median of ≈2%; the total contribution of clump light ranges from 10% to 25%. The median intrinsic clump size and stellar mass are ~1 kpc and ~10^9 M_☉, in the ranges for clumps identified in rest-UV or line emission in other studies. The clump sizes and masses in the subset of disks are broadly consistent with expectations for clump formation through gravitational instabilities in gas-rich, turbulent disks given the host galaxies' global properties. By combining the NIC2 data with Advanced Camera for Surveys (ACS)/F814W imaging available for one source, and adaptive-optics-assisted SINFONI Hα data for another, we infer modest color, M/L, and stellar age variations within each galaxy. In these two objects, sets of clumps identified at different wavelengths do not fully overlap; NIC2-identified clumps tend to be redder/older than ACS- or Hα-identified clumps without rest-frame optical counterparts. There is evidence for a systematic trend of older ages at smaller galactocentric radii among the clumps, consistent with scenarios where inward migration of clumps transports material toward the central regions. From constraints on a bulge-like component at radii ≾1-3 kpc, none of the five disks in our sample appears to contain a compact massive stellar core, and we do not discern a trend of bulge stellar mass fraction with stellar age of the galaxy. Further observations are necessary to probe the buildup of stellar bulges and the role of clumps in this process

Mapping the complete glycoproteome of virion-derived HIV-1 gp120 provides insights into broadly neutralizing antibody binding

The surface envelope glycoprotein (SU) of Human immunodeficiency virus type 1 (HIV-1), gp120SU plays an essential role in virus binding to target CD4+ T-cells and is a major vaccine target. Gp120 has remarkably high levels of N-linked glycosylation and there is considerable evidence that this “glycan shield” can help protect the virus from antibody-mediated neutralization. In recent years, however, it has become clear that gp120 glycosylation can also be included in the targets of recognition by some of the most potent broadly neutralizing antibodies. Knowing the site-specific glycosylation of gp120 can facilitate the rational design of glycopeptide antigens for HIV vaccine development. While most prior studies have focused on glycan analysis of recombinant forms of gp120, here we report the first systematic glycosylation site analysis of gp120 derived from virions produced by infected T lymphoid cells and show that a single site is exclusively substituted with complex glycans. These results should help guide the design of vaccine immunogens

Mergers and Mass Accretion Rates in Galaxy Assembly: The Millennium Simulation Compared to Observations of z~2 Galaxies

Recent observations of UV-/optically selected, massive star forming galaxies at z~2 indicate that the baryonic mass assembly and star formation history is dominated by continuous rapid accretion of gas and internal secular evolution, rather than by major mergers. We use the Millennium Simulation to build new halo merger trees, and extract halo merger fractions and mass accretion rates. We find that even for halos not undergoing major mergers the mass accretion rates are plausibly sufficient to account for the high star formation rates observed in z~2 disks. On the other hand, the fraction of major mergers in the Millennium Simulation is sufficient to account for the number counts of submillimeter galaxies (SMGs), in support of observational evidence that these are major mergers. When following the fate of these two populations in the Millennium Simulation to z=0, we find that subsequent mergers are not frequent enough to convert all z~2 turbulent disks into elliptical galaxies at z=0. Similarly, mergers cannot transform the compact SMGs/red sequence galaxies at z~2 into observed massive cluster ellipticals at z=0. We argue therefore, that secular and internal evolution must play an important role in the evolution of a significant fraction of z~2 UV-/optically and submillimeter selected galaxy populations.Comment: 5 pages, 4 figures, Accepted for publication in Ap

The Impact of cold gas accretion above a mass floor on galaxy scaling relations

Using the cosmological baryonic accretion rate and normal star formation efficiencies, we present a very simple model for star-forming galaxies (SFGs) that accounts for the mass and redshift dependencies of the SFR-Mass and Tully-Fisher relations from z=2 to the present. The time evolution follows from the fact that each modelled galaxy approaches a steady state where the SFR follows the (net) cold gas accretion rate. The key feature of the model is a halo mass floor M_{min}~10^{11} below which accretion is quenched in order to simultaneously account for the observed slopes of the SFR-Mass and Tully-Fischer relations. The same successes cannot be achieved via a star-formation threshold (or delay) nor by varying the SF efficiency or the feedback efficiency. Combined with the mass ceiling for cold accretion due to virial shock heating, the mass floor M_{min} explains galaxy "downsizing", where more massive galaxies formed earlier and over a shorter period of time. It turns out that the model also accounts for the observed galactic baryon and gas fractions as a function of mass and time, and the cosmic SFR density from z~6 to z=0, which are all resulting from the mass floor M_{min}. The model helps to understand that it is the cosmological decline of accretion rate that drives the decrease of cosmic SFR density between z~2 and z=0 and the rise of the cosmic SFR density allows us to put a constraint on our main parameter M_{min}~10^{11} solar masses. Among the physical mechanisms that could be responsible for the mass floor, we view that photo-ionization feedback (from first in-situ hot stars) lowering the cooling efficiency is likely to play a large role.Comment: 19pages, 14 figures, accepted to ApJ, updated reference

The SINS Survey: Broad Emission Lines in High-Redshift Star-Forming Galaxies

High signal-to-noise, representative spectra of star-forming galaxies at z~2, obtained via stacking, reveal a high-velocity component underneath the narrow H-alpha and [NII] emission lines. When modeled as a single Gaussian, this broad component has FWHM > 1500 km/s; when modeled as broad wings on the H-alpha and [NII] features, it has FWHM > 500 km/s. This feature is preferentially found in the more massive and more rapidly star-forming systems, which also tend to be older and larger galaxies. We interpret this emission as evidence of either powerful starburst-driven galactic winds or active supermassive black holes. If galactic winds are responsible for the broad emission, the observed luminosity and velocity of this gas imply mass outflow rates comparable to the star formation rate. On the other hand, if the broad line regions of active black holes account for the broad feature, the corresponding black holes masses are estimated to be an order of magnitude lower than those predicted by local scaling relations, suggesting a delayed assembly of supermassive black holes with respect to their host bulges.Comment: 11 pages, 5 figures. Accepted version, incorporating referee comments, including changes to title, abstract, figures, and discussion sectio

Possible Signatures of a Cold-Flow Disk from MUSE using a z=1 galaxy--quasar pair towards SDSSJ1422-0001

We use a background quasar to detect the presence of circum-galactic gas around a $z=0.91$ low-mass star forming galaxy. Data from the new Multi Unit Spectroscopic Explorer (MUSE) on the VLT show that the host galaxy has a dust-corrected star-formation rate (SFR) of 4.7$\pm$0.2 Msun/yr, with no companion down to 0.22 Msun/yr (5 $\sigma$) within 240 kpc (30"). Using a high-resolution spectrum (UVES) of the background quasar, which is fortuitously aligned with the galaxy major axis (with an azimuth angle $\alpha$ of only $15^\circ$), we find, in the gas kinematics traced by low-ionization lines, distinct signatures consistent with those expected for a "cold flow disk" extending at least 12 kpc ($3\times R_{1/2}$). We estimate the mass accretion rate $\dot M_{\rm in}$ to be at least two to three times larger than the SFR, using the geometric constraints from the IFU data and the HI column density of $\log N_{\rm HI} \simeq 20.4$ obtained from a {\it HST}/COS NUV spectrum. From a detailed analysis of the low-ionization lines (e.g. ZnII, CrII, TiII, MnII, SiII), the accreting material appears to be enriched to about 0.4 $Z_\odot$ (albeit with large uncertainties: $\log Z/Z_\odot=-0.4~\pm~0.4$), which is comparable to the galaxy metallicity ($12+\log \rm O/H=8.7\pm0.2$), implying a large recycling fraction from past outflows. Blue-shifted MgII and FeII absorptions in the galaxy spectrum from the MUSE data reveal the presence of an outflow. The MgII and FeII doublet ratios indicate emission infilling due to scattering processes, but the MUSE data do not show any signs of fluorescent FeII* emission.Comment: 17 pages, 11 figures, in press (ApJ), minor edits after the proofs. Data available at http://muse-vlt.eu/science/j1422

Constraints on the assembly and dynamics of galaxies. II. Properties of kiloparsec-scale clumps in rest-frame optical emission of z ~ 2 star-forming galaxies

We study the properties of luminous stellar clumps identified in deep, high resolution HST/NIC2 F160W imaging at 1.6um of six z~2 star-forming galaxies with existing near-IR integral field spectroscopy from SINFONI at the VLT. Individual clumps contribute ~0.5%-15% of the galaxy-integrated rest-frame ~5000A emission, with median of about 2%; the total contribution of clump light ranges from 10%-25%. The median intrinsic clump size and stellar mass are ~1kpc and log(Mstar[Msun])~9, in the ranges for clumps identified in rest-UV or line emission in other studies. The clump sizes and masses in the subset of disks are broadly consistent with expectations for clump formation via gravitational instabilities in gas-rich, turbulent disks given the host galaxies' global properties. By combining the NIC2 data with ACS/F814W imaging available for one source, and AO-assisted SINFONI Halpha data for another, we infer modest color, M/L, and stellar age variations within each galaxy. In these two objects, sets of clumps identified at different wavelengths do not fully overlap; NIC2-identified clumps tend to be redder/older than ACS- or Halpha-identified clumps without rest-frame optical counterparts. There is evidence for a systematic trend of older ages at smaller galactocentric radii among the clumps, consistent with scenarios where inward migration of clumps transports material towards the central regions. From constraints on a bulge-like component at radii <1-3kpc, none of the five disks in our sample appears to contain a compact massive stellar core, and we do not discern a trend of bulge stellar mass fraction with stellar age of the galaxy. Further observations are necessary to probe the build-up of stellar bulges and the role of clumps in this process.Comment: 29 pages, 11 figures. Revised version accepted for publication in the Astrophysical Journa

High Sensitivity Array Observations of the z=1.87 Sub-Millimeter Galaxy GOODS 850-3

We present sensitive phase-referenced VLBI results on the radio continuum emission from the z=1.87 luminous submillimeter galaxy (SMG) GOODS 850-3. The observations were carried out at 1.4 GHz using the High Sensitivity Array (HSA). Our sensitive tapered VLBI image of GOODS 850-3 at 0.47 x 0.34 arcsec (3.9 x 2.9 kpc) resolution shows a marginally resolved continuum structure with a peak flux density of 148 \pm 38 uJy/beam, and a total flux density of 168 \pm 73 uJy, consistent with previous VLA and MERLIN measurements. The derived intrinsic brightness temperature is > 5 \pm 2 x 10^3 K. The radio continuum position of this galaxy coincides with a bright and extended near-infrared source that nearly disappears in the deep HST optical image, indicating a dusty source of nearly 9 kpc in diameter. No continuum emission is detected at the full VLBI resolution (13.2 x 7.2 mas, 111 x 61 pc), with a 4-sigma point source upper limit of 26 uJy/beam, or an upper limit to the intrinsic brightness temperature of 4.7 x 10^5 K. The extent of the observed continuum source at 1.4 GHz and the derived brightness temperature limits are consistent with the radio emission (and thus presumably the far-infrared emission) being powered by a major starburst in GOODS 850-3, with a star formation rate of ~2500 M_sun/yr. Moreover, the absence of any continuum emission at the full resolution of the VLBI observations indicates the lack of a compact radio AGN source in this z=1.87 SMG.Comment: 19 pages, 4 figures, accepted for publication in A

New CO detections of lensed submillimeter galaxies in A2218: Probing molecular gas in the LIRG regime at high redshift

Context: Submillimeter galaxies (SMGs) are distant, dusty galaxies undergoing star formation at prodigious rates. Recently there has been major progress in understanding the nature of the bright SMGs (i.e. S(850um)>5mJy). The samples for the fainter SMGs are small and are currently in a phase of being built up through identification studies. Aims: We study the molecular gas content in two SMGs, SMMJ163555 and SMMJ163541, at z=1.034 and z=3.187 with unlensed submm fluxes of 0.4mJy and 6.0mJy. Both SMGs are gravitationally lensed by the foreground cluster A2218. Methods: IRAM Plateau de Bure Interferometry observations at 3mm were obtained for the lines CO(2-1) for SMMJ163555 and CO(3-2) for SMMJ163541. Additionally we obtained CO(4-3) for the candidate z=4.048 SMMJ163556 with an unlensed submm flux of 2.7mJy. Results: CO(2-1) was detected for SMMJ163555 at z=1.0313 with an integrated line intensity of 1.2+-0.2Jy km/s and a line width of 410+-120 km/s. From this a gas mass of 1.6x10^9 Msun is derived and a star formation efficiency of 440Lsun/Msun is estimated. CO(3-2) was detected for SMMJ163541 at z=3.1824, possibly with a second component at z=3.1883, with an integrated line intensity of 1.0+-0.1 Jy km/s and a line width of 280+-50 km/s. From this a gas mass of 2.2x10^10 Msun is derived and a star formation efficiency of 1000 Lsun/Msun is estimated. For SMMJ163556 the CO(4-3) is undetected within the redshift range 4.035-4.082 down to a sensitivity of 0.15 Jy km/s. Conclusions: Our CO line observations confirm the optical redshifts for SMMJ163555 and SMMJ163541. The CO line luminosity L'_CO for both galaxies is consistent with the L_FIR-L'_CO relation. SMMJ163555 has the lowest FIR luminosity of all SMGs with a known redshift and is one of the few high redshift LIRGs whose properties can be estimated prior to ALMA.Comment: 7 pages, 4 figures. A&A in pres