ISO -LWS two-colour diagram of young stellar objects

We present a [60-100] versus [100-170]μm two-colour diagram for a sample of 61 young stellar objects (YSOs) observed with the Long Wavelength Spectrometer (LWS) on-board the Infrared Space Observatory (ISO). The sample consists of 17 Class 0 sources, 15 Class I, nine Bright Class I (Lbol>104Lsolar) and 20 Class II (14 Herbig Ae/Be stars and six T Tauri stars). We find that each class occupies a well-defined region in our diagram with colour temperatures increasing from Class 0 to Class II. Therefore the [60-100] versus [100-170] two-colour diagram is a powerful and simple tool to derive from future (e.g. with the Herschel Space Observatory) photometric surveys the evolutionary status of YSOs. The advantage over other tools already developed is that photometry at other wavelengths is not required: three flux measurements are enough to derive the evolutionary status of a source. As an example we use the colours of the YSO IRAS 18148-0440 to classify it as Class I. The main limitation of this work is the low spatial resolution of the LWS which, for some objects, causes a high uncertainty in the measured fluxes due to background emission or to source confusion inside the LWS beam

Strong H_2O and high-J CO emission towards the Class 0 protostar L1448-mm

The spectrum of the Class 0 source L1448-mm has been measured over the wavelength range extending from 6 to 190 mu m with the Long Wavelength Spectrometer (LWS) and the Short Wavelength Spectrometer (SWS) on the Infrared Space Observatory (ISO). The far infrared spectrum is dominated by strong emission from gaseous H_2O and from CO transitions with rotational quantum numbers J >= 14; in addition, the H_2 pure rotational lines S(3), S(4) and S(5), the OH fundamental line at 119 mu m, as well as emission from [O I] 63 mu m and [C Ii] 158 mu m are also observed. The strong CO and water emission can be consistently explained as originating in a warm gas component at T ~ 700-1400 K and n_H_2 ~ (3-50) 10(4 ) cm(-3) , which fills about 0.2-2% of the ~ 75\arcsec LWS field of view (corresponding, assuming a single emitting region, to a physical size of about (3-12)\arcsec or (0.5-2) 10(-2) pc at d = 300 pc). We derive an H_2O/CO abundance ratio ~ 5, which, assuming a standard CO/H_2 abundance of 10(-4) , corresponds to H_2O/H_2 ~ 5 10(-4) . This value implies that water is enhanced by about a factor ~ 10(3) with respect to its expected abundance in the ambient gas. This is consistent with models of warm shocked regions which predict that most of the free atomic oxygen will be rapidly converted into water once the temperature of the post-shocked gas exceeds ~ 300 K. The relatively high density and compact size inferred for this emission may suggest an origin in the shocked region along the molecular jet traced by SiO and EHV CO millimeter line emission. Further support is given by the fact that the observed enhancement in H_2O can be explained by shock conditions similar to those expected to produce the abundant SiO observed in the region. L1448-mm shows the largest water abundance so far observed by ISO amongst young sources displaying outflow activity; we argue that the occurrence of multiple shocks over a relatively short interval of time, like that evidenced in the surroundings of L1448-mm, could have contributed to enrich the molecular jet with a high H_2O column density. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) with the participation of ISAS and NAS

VizieR Online Data Catalog: Catalog of dense cores in Aquila from Herschel (Konyves+, 2015)

Based on Herschel Gould Belt survey (Andre et al., 2010A&A...518L.102A) observations of the Aquila cloud complex, and using the multi-scale, multi-wavelength source extraction algorithm getsources (Men'shchikov et al., 2012A&A...542A..81M), we identified a total of 749 dense cores, including 685 starless cores and 64 protostellar cores. The observed properties of all dense cores are given in tablea1.dat, and their derived properties are listed in tablea2.dat. (4 data files)

A traffic analyzer for multiple SpaceWire links

Modern space missions are becoming increasingly complex: the interconnection of the units in a satellite is now a network of terminals linked together through routers, where devices with different level of automation and intelligence share the same data-network. The traceability of the network transactions is performed mostly at terminal level through log analysis and hence it is difficult to verify in real time the reliability of the interconnections and the interchange protocols. To improve and ease the traffic analysis in a SpaceWire network we implemented a low-level link analyzer, with the specific goal to simplify the integration and test phases in the development of space instrumentation. The traffic analyzer collects signals coming from pod probes connected in-series on the interested links between two SpaceWire terminals. With respect to the standard traffic analyzers, the design of this new tool includes the possibility to internally reshape the LVDS signal. This improvement increases the robustness of the analyzer towards environmental noise effects and guarantees a deterministic delay on all analyzed signals. The analyzer core is implemented on a Xilinx FPGA, programmed to decode the bidirectional LVDS signals at Link and Network level. Successively, the core packetizes protocol characters in homogeneous sets of time ordered events. The analyzer provides time-tagging functionality for each characters set, with a precision down to the FPGA Clock, i.e. about 20nsec in the adopted HW environment. The use of a common time reference for each character stream allows synchronous performance measurements. The collected information is then routed to an external computer for quick analysis: this is done via high-speed USB2 connection. With this analyzer it is possible to verify the link performances in terms of induced delays in the transmitted signals. A case study focused on the analysis of the Time-Code synchronization in presence of a SpaceWire Router is shown in this paper as well

VizieR Online Data Catalog: Dense cores in Taurus L1495 cloud (Marsh+, 2016)

The observational data on which the present catalogue is based consists of a set of images of the L1495 cloud in the Taurus star-forming region, made as part of the HGBS (Andre et al. 2010). The data were taken using PACS at 70, 160, 250, 350 and 500 microns in fast-scanning (60"/s) parallel mode. (2 data files)

Fluorescence-based bowel anastomosis perfusion evaluation: results from the IHU-IRCAD-EAES EURO-FIGS registry

Anastomotic leakage (AL) is one of the dreaded complications following surgery in the digestive tract. Near-infrared fluorescence (NIRF) imaging is a means to intraoperatively visualize anastomotic perfusion, facilitating fluorescence image-guided surgery (FIGS) with the purpose to reduce the incidence of AL. The aim of this study was to analyze the current practices and results of NIRF imaging of the anastomosis in digestive tract surgery through the EURO-FIGS registry