A framework for overall sustainability assessment of local small-scale energy production - demonstration of an approach

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Light and colour of cirrus, translucent and opaque dust in the high-latitude area of LDN 1642

We have performed a 5-colour surface photometric study of the high-galactic-latitude area of dark nebula LDN 1642. Scattered light properties are presented of diffuse, translucent and opaque dust over the range of 3500 -- 5500 A. Far infrared absolute photometry at 200 um improves the precision of and provides a zero point to the extinction. The intensity of the scattered light depends on dust column density in a characteristic way: for optically thin dust the intensity first increases linearly, then turns to a saturation value; at still larger extinctions the intensity turns down to a slow decrease. The $A_V$ value of the saturated intensity maximum shifts in a systematic way, from $A_V\approx$ 1.5 mag at 3500 A, to $\sim 3$ mag at 5500 A. The intensity curves offer a straight-forward explanation for the behaviour of the scattered-light colours. At the intensity peak the colour agrees with the integrated starlight colour, while it is bluer at the low- and redder at the high-column-density side of the peak, respectively. These colour changes are a direct consequence of the wavelength dependence of the extinction. We have compared the colours of the LDN 1642 area with other relevant observational studies: high-latitude diffuse/translucent clouds, wide-field cirrus dust; and externally illuminated AGB-star envelopes. For extragalactic low-surface-brightness sources cirrus is an unwanted foreground contaminant. Our results for cirrus colours can help to distinguish cases where a diffuse plume or stream, apparently associated with a galaxy or a group or cluster, is more likely a local cirrus structure. Keywords: ISM: dust, extinction -- ISM: clouds, individual LDN 1642 -- Galaxy: solar neighbourhood -- Astronomical instruments, methods and techniques: methods -- Physical data and processes: scatteringComment: 20 pages, 10 figures, accepted for publication in MNRAS, published as MNRAS advance article on June 27 202

A multi-wavelength view of the central kiloparsec region in the Luminous Infrared Galaxy NGC1614

The Luminous Infrared Galaxy NGC1614 hosts a prominent circumnuclear ring of star formation. However, the nature of the dominant emitting mechanism in its central ~100 pc is still under debate. We present sub-arcsecond angular resolution radio, mid-infrared, Pa-alpha, optical, and X-ray observations of NGC1614, aimed at studying in detail both the circumnuclear ring and the nuclear region. The 8.4 GHz continuum emission traced by the Very Large Array (VLA) and the Gemini/T-ReCS 8.7 micron emission, as well as the Pa-alpha line emission, show remarkable morphological similarities within the star-forming ring, suggesting that the underlying emission mechanisms are tightly related. We used an HST/NICMOS Pa-alpha map of similar resolution to our radio maps to disentangle the thermal free-free and non-thermal synchrotron radio emission, from which we obtained the intrinsic synchrotron power-law for each individual region within the central kpc of NGC1614. The radio ring surrounds a relatively faint, steep-spectrum source at the very center of the galaxy, suggesting that the central source is not powered by an AGN, but rather by a compact (r < 90 pc) starburst. Chandra X-ray data also show that the central kpc region is dominated by starburst activity, without requiring the existence of an AGN. We also used publicly available infrared data to model-fit the spectral energy distribution of both the starburst ring and a putative AGN in NGC1614. In summary, we conclude that there is no need to invoke an AGN to explain the observed bolometric properties of the galaxy.Comment: 13 pages, 7 figures, 5 tables. Accepted for publication in Ap

An Extremely Deep Wide-Field Near-Infrared Survey: Bright Galaxy Counts and Local Large Scale Structure

We present a deep, wide-field near-infrared (NIR) survey over five widely separated fields at high Galactic latitude covering a total of ~ 3 deg^2 in J, H, and Ks. The deepest areas of the data (~ 0.25 deg^2) extend to a 5 sigma limiting magnitude of JHKs > 24 in the AB magnitude system. Although depth and area vary from field to field, the overall depth and large area of this dataset make it one of the deepest wide-field NIR imaging surveys to date. This paper discusses the observations, data reduction, and bright galaxy counts in these fields. We compare the slope of the bright galaxy counts with the Two Micron All Sky Survey (2MASS) and other counts from the literature and explore the relationship between slope and supergalactic latitude. The slope near the supergalactic equator is sub- Euclidean on average pointing to the possibility of a decreasing average space density of galaxies by ~ 10-15% over scales of ~ 250-350 Mpc. On the contrary, the slope at high supergalactic latitudes is strongly super-Euclidean on average suggesting an increase in the space density of galaxies as one moves from the voids just above and below the supergalactic plane out to distances of ~ 250-350 Mpc. These results suggest that local large scale structure could be responsible for large discrepancies in the measured slope between different studies in the past. In addition, the local universe away from the supergalactic plane appears to be underdense by ~ 25-100% relative to the space densities of a few hundred megaparsecs distant. Subject headings: cosmology: observations and large scale structure of universe-galaxies: fundamental parameters (counts)-infrared: galaxiesComment: Accepted to ApJS, 18 Pages, 14 Figures, 8 Table

ESO Imaging Survey: infrared observations of CDF-S and HDF-S

This paper presents infrared data obtained from observations carried out at the ESO 3.5m New Technology Telescope (NTT) of the Hubble Deep Field South (HDF-S) and the Chandra Deep Field South (CDF-S). These data were taken as part of the ESO Imaging Survey (EIS) program, a public survey conducted by ESO to promote follow-up observations with the VLT. In the HDF-S field the infrared observations cover an area of ~53 square arcmin, encompassing the HST WFPC2 and STIS fields, in the JHKs passbands. The seeing measured in the final stacked images ranges from 0.79" to 1.22" and the median limiting magnitudes (AB system, 2" aperture, 5sigma detection limit) are J_AB~23.0, H_AB~22.8 and K_AB~23.0 mag. Less complete data are also available in JKs for the adjacent HST NICMOS field. For CDF-S, the infrared observations cover a total area of \~100 square arcmin, reaching median limiting magnitudes (as defined above) of J_AB~23.6 and K_AB~22.7 mag. For one CDF-S field H-band data are also available. This paper describes the observations and presents the results of new reductions carried out entirely through the un-supervised, high-throughput EIS Data Reduction System and its associated EIS/MVM C++-based image processing library developed, over the past 5 years, by the EIS project and now publicly available. The paper also presents source catalogs extracted from the final co-added images which are used to evaluate the scientific quality of the survey products, and hence the performance of the software. This is done comparing the results obtained in the present work with those obtained by other authors from independent data and/or reductions carried out with different software packages and techniques. The final science-grade catalogs and co-added images are available at CDS.Comment: Accepted for publication in A&A, 13 pages, 12 figures; a full resolution version of the paper is available from http://www.astro.ku.dk/~lisbeth/eisdata/papers/4528.pdf ; related catalogs and images are available through http://www.astro.ku.dk/~lisbeth/eisdata

ESO Imaging Survey: Infrared Deep Public Survey

This paper presents new J and Ks data obtained from observations conducted at the ESO 3.5m New Technology Telescope using the SOFI camera. These data were taken as part of the ESO Imaging Survey Deep Public Survey (DPS) and significantly extend the earlier optical/infrared EIS-DEEP survey presented in a previous paper. The DPS-IR survey comprises two observing strategies: shallow Ks observations providing nearly full coverage of pointings with complementary multi-band optical data and deeper J and Ks observations of the central parts of these fields. The DPS-IR survey provides a coverage of roughly 2.1 square degrees in Ks with 0.63 square degrees to fainter magnitudes and also covered in J, over three independent regions of the sky. The goal of the present paper is to describe the observations, the data reduction procedures, and to present the final survey products. The astrometric solution with an estimated accuracy of <0.15" is based on the USNO catalog. The final stacked images presented here number 89 and 272, in J and Ks, respectively, the latter reflecting the larger surveyed area. The J and Ks images were taken with a median seeing of 0.77" and 0.8". The images reach a median 5sigma limiting magnitude of J_AB~23.06 in an aperture of 2", while the corresponding limiting magnitude in Ks_AB is ~21.41 and ~22.16 mag for the shallow and deep strategies. Overall, the observed limiting magnitudes are consistent with those originally proposed. The quality of the data has been assessed by comparing the measured magnitude of sources at the bright end directly with those reported by the 2MASS survey and at the faint end by comparing the counts of galaxies and stars with those of other surveys to comparable depth and to model predictions. The final science-grade catalogs and images are available at CDS.Comment: Accepted for publication in A&A, 14 pages, 8 figures, a full resolution version of the paper is available from http://www.astro.ku.dk/~lisbeth/eisdata/papers/5019.pd

Star formation in Cometary globule 1: the second generation

C18O spectral line observations, NIR spectrosopy, narrow and broad band NIR imaging and stellar J,H,Ks photometry are used to analyse the structure of the archetype cometary globule 1 (CG 1) head and the extinction of stars in its direction. A young stellar object (YSO) associated with a bright NIR nebulosity and a molecular hydrogen object (a probable obscured HH-object), were discovered in the globule. Molecular hydrogen and Br_gamma line emission is seen in the direction of the YSO. The observed maximum optical extinction in the globule head is 9.2 magnitudes. The peak N(H2) column density and the total mass derived from the extinction are 9.0 10^21 cm-2 and and 16.7 Msun (d/300pc)^2. C18O emission in the globule head is detected in a 1.5'' by 4' area with a sharp maximum SW of the YSO. Three regions can be discerned in C18O line velocity and excitation temperature. Because of variations in the C18O excitation temperature the integrated line emission does not follow the optical extinction. It is argued that the variations in the C18O excitation temperatures are caused by radiative heating by NX Pup and interaction of the YSO with the parent cloud. No indication of a strong molecular outflow from the YSO is evident in the molecular line data. The IRAS point source 07178-4429 located in the CG 1 head resolves into two sources in the HIRES enhanced IRAS images. The 12 and 25 micron emission originates mainly in the star NX Puppis and the 60 and 100 micron emission in the YSO. The IRAS FIR luminosity of the YSO is 3.1 Lsun.Comment: Language checked v2. Accepted for publication in A&A. 16 pages, 20 figures. C18O data will be available electronicall

VLT-VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies II. Evidence for shock ionization caused by tidal forces in the extra-nuclear regions of interacting and merging LIRGs

LIRGs are an important class of objects in the low-z universe bridging the gap between normal spirals and the strongly interacting and starbursting ULIRGs. Studies of their 2D physical properties are still lacking. We aim to understand the nature and origin of the ionization mechanisms operating in the extranuclear regions of LIRGs as a function of the interaction phase and L_IR by using IFS data obtained with VIMOS. Our analysis is based on over 25300 spectra of 32 LIRGs covering all types of morphologies and the entire 10^11-10^12 L_sun range. We found strong evidence for shock ionization, with a clear trend with the dynamical status of the system. Specifically, we quantified the variation with interaction phase of several line ratios indicative of the excitation degree. While the [NII]/Ha ratio does not show any significant change, the [SII]/Ha and [OI]/Ha ratios are higher for more advanced interaction stages. We constrained the main mechanisms causing the ionization in the extra-nuclear regions using diagnostic diagrams. Isolated systems are mainly consistent with ionization caused by young stars. Large fractions of the extra-nuclear regions in interacting pairs and more advanced mergers are consistent with ionization caused by shocks. This is supported by the relation between the excitation degree and the velocity dispersion of the ionized gas, which we interpret as evidence for shock ionization in interacting galaxies and advanced mergers but not in isolated galaxies. This relation does not show any dependence with L_IR. All this indicates that tidal forces play a key role in the origin of the ionizing shocks in the extra-nuclear regions. We also showed what appears to be a common [OI]/Ha-sigma relation for the extranuclear ionized gas in interacting (U)LIRGs. This needs to be investigated further with a larger sample of ULIRGs.Comment: Accepted for publication in Astronomy and Astrophysics. Some figures were removed due to space limitations. A version with the whole set of figures can be seen at http://www.damir.iem.csic.es/extragalactic/publications/publications.htm

Principles for the socially responsible use of conservation monitoring technology and data

Wildlife conservation and research benefits enormously from automated and interconnected monitoring tools. Some of these tools, such as drones, remote cameras, and social media, can collect data on humans, either accidentally or deliberately. They can therefore be thought of as conservation surveillance technologies (CSTs). There is increasing evidence that CSTs, and the data they yield, can have both positive and negative impacts on people, raising ethical questions about how to use them responsibly. CST use may accelerate because of the COVID-19 pandemic, adding urgency to addressing these ethical challenges. We propose a provisional set of principles for the responsible use of such tools and their data: (a) recognize and acknowledge CSTs can have social impacts; (b) deploy CSTs based on necessity and proportionality relative to the conservation problem; (c) evaluate all potential impacts of CSTs on people; (d) engage with and seek consent from people who may be observed and/or affected by CSTs; (e) build transparency and accountability into CST use; (f) respect peoples' rights and vulnerabilities; and (g) protect data in order to safeguard privacy. These principles require testing and could conceivably benefit conservation efforts, especially through inclusion of people likely to be affected by CSTs.Peer reviewe