Changement climatique et éducation

Education dealing with climate change is part of the UNFCCC Paris Agreement ratified in 2016. Education is precious to act on a broad scale on people’s behavior and society choices. It is also a demand from the youth who, more than others, is facing a worrying future, but can be helped for a mobilization of energies. Numerous initiatives emerge to implement it, while its systemic and interdisciplinary character requests a significant evolution of school’s curricula. The role of teachers is crucial and accompanying them essential. We therefore consider critical to propose pedagogical resources, which are based upon the best current knowledge on climate, i.e. the reports from the Intergovernmental Panel on Climate Change (IPCC)

Teacher's guide book for primary and secondary school

There is an urgent need for collective action to mitigate the consequences of climate change and adapt to unavoidable changes. The complexity of climate change issues can pose educational challenges. Nonetheless, education has a key role to play in ensuring that younger generations have the required knowledge and skills to understand issues surrounding climate change, to avoid despair, to take action, and to be prepared to live in a changing world. The Office for Climate Education (OCE) was founded in 2018 to promote strong international cooperation between scientific organisations, educational institutions and NGOs. The overall aim of the OCE is to ensure that the younger generations of today and tomorrow are educated about climate change. Teachers have a key role to play in their climate education and it is essential that they receive sufficient support to enable them to implement effective lessons on climate change. The OCE has developed a range of educational resources and professional development modules to support them in teaching about climate change with active pedagogy

Changement climatique et éducation

Education dealing with climate change is part of the UNFCCC Paris Agreement ratified in 2016. Education is precious to act on a broad scale on people’s behavior and society choices. It is also a demand from the youth who, more than others, is facing a worrying future, but can be helped for a mobilization of energies. Numerous initiatives emerge to implement it, while its systemic and interdisciplinary character requests a significant evolution of school’s curricula. The role of teachers is crucial and accompanying them essential. We therefore consider critical to propose pedagogical resources, which are based upon the best current knowledge on climate, i.e. the reports from the Intergovernmental Panel on Climate Change (IPCC)

Shocked Molecular Hydrogen in the 3C 326 Radio Galaxy System

The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by very strong molecular hydrogen emission lines on a faint IR continuum. The H2 emission originates in the northern component of a double-galaxy system associated with 3C 326. The integrated luminosity in H2 pure-rotational lines is 8.0E41 erg/s, which corresponds to 17% of the 8-70 micron luminosity of the galaxy. A wide range of temperatures (125-1000 K) is measured from the H2 0-0 S(0)-S(7) transitions, leading to a warm H2 mass of 1.1E9 Msun. Low-excitation ionic forbidden emission lines are consistent with an optical LINER classification for the active nucleus, which is not luminous enough to power the observed H2 emission. The H2 could be shock-heated by the radio jets, but there is no direct indication of this. More likely, the H2 is shock-heated in a tidal accretion flow induced by interaction with the southern companion galaxy. The latter scenario is supported by an irregular morphology, tidal bridge, and possible tidal tail imaged with IRAC at 3-9 micron. Unlike ULIRGs, which in some cases exhibit H2 line luminosities of comparable strength, 3C 326 shows little star-formation activity (~0.1 Msun/yr). This may represent an important stage in galaxy evolution. Starburst activity and efficient accretion onto the central supermassive black hole may be delayed until the shock-heated H2 can kinematically settle and coolComment: 27 pages, 7 figures, accepted for publication in the Astrophysical Journa

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Mapping warm molecular hydrogen with Spitzer's Infrared Array Camera (IRAC)

Photometric maps, obtained with Spitzer's Infrared Array Camera (IRAC), can provide a valuable probe of warm molecular hydrogen within the interstellar medium. IRAC maps of the supernova remnant IC443, extracted from the Spitzer archive, are strikingly similar to spectral line maps of the H2 pure rotational transitions that we obtained with the Infrared Spectrograph (IRS) instrument on Spitzer. IRS spectroscopy indicates that IRAC Bands 3 and 4 are indeed dominated by the H2 v=0-0 S(5) and S(7) transitions, respectively. Modeling of the H2 excitation suggests that Bands 1 and 2 are dominated by H2 v=1-0 O(5) and v=0-0 S(9). Large maps of the H2 emission in IC433, obtained with IRAC, show band ratios that are inconsistent with the presence of gas at a single temperature. The relative strengths of IRAC Bands 2, 3, and 4 are consistent with pure H2 emission from shocked material with a power-law distribution of gas temperatures. CO vibrational emissions do not contribute significantly to the observed Band 2 intensity. Assuming that the column density of H2 at temperatures T to T+dT is proportional to T raised to the power -b for temperatures up to 4000 K, we obtained a typical estimate of 4.5 for b. The power-law index, b, shows variations over the range 3 to 6 within the set of different sight-lines probed by the maps, with the majority of sight-lines showing b in the range 4 to 5. The observed power-law index is consistent with the predictions of simple models for paraboloidal bow shocks.Comment: 27 pages, including 11 figures. Accepted for publication in Ap

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Spitzer spectral line mapping of protostellar outflows: II H2 emission in L1157

We present an analysis of Spitzer-IRS spectroscopic maps of the L1157 protostellar outflow in the H2 pure-rotational lines from S(0) to S(7). The aim of this work is to derive the physical conditions pertaining to the warm molecular gas and study their variations within the flow. The mid-IR H2 emission follows the morphology of the precessing flow, with peaks correlated with individual CO clumps and H2 2.12{\mu}m ro-vibrational emission. More diffuse emission delineating the CO cavities is detected only in the low-laying transitions, with J(lower) less or equal to 2. The H2 line images have been used to construct 2D maps of N(H2), H2 ortho-to-para ratio and temperature spectral index beta, in the assumption of a gas temperature stratification where the H2 column density varies as T^(beta). Variations of these parameters are observed along the flow. In particular, the ortho-to-para ratio ranges from 0.6 to 2.8, highlighting the presence of regions subject to recent shocks where the ortho-to-para ratio has not had time yet to reach the equilibrium value. Near-IR spectroscopic data on ro-vibrational H2 emission have been combined with the mid-IR data and used to derive additional shock parameters in the brightest blue- and red-shifted emission knots. A high abundance of atomic hydrogen (H/H2 about 0.1-0.3) is implied by the observed H2 column densities, assuming n(H2) values as derived by independent SiO observations. The presence of a high fraction of atomic hydrogen, indicates that a partially-dissociative shock component should be considered for the H2 excitation in these localized regions. However, planar shock models, either of C- or J-type, are not able to consistently reproduce all the physical parameters derived from our analysis of the H2 emission. Globally, H2 emission contributes to about 50% of the total shock radiated energy in the L1157 outflow.Comment: 31 pages, 9 figure, Accepted for publication on Ap

Spitzer observations of HH54 and HH7-11: mapping the H2 ortho-to-para ratio in shocked molecular gas

We report the results of spectroscopic mapping observations carried out toward the Herbig-Haro objects HH7-11 and HH54 over the 5.2 - 37 micron region using the Infrared Spectrograph of the Spitzer Space Telescope. These observations have led to the detection and mapping of the S(0) - S(7) pure rotational lines of molecular hydrogen, together with emissions in fine structure transitions of Ne+, Si+, S, and Fe+. The H2 rotational emissions indicate the presence of warm gas with a mixture of temperatures in the range 400 - 1200 K, consistent with the expected temperature behind nondissociative shocks of velocity ~ 10 - 20 km/s, while the fine structure emissions originate in faster shocks of velocity 35 - 90 km/s that are dissociative and ionizing. Maps of the H2 line ratios reveal little spatial variation in the typical admixture of gas temperatures in the mapped regions, but show that the H2 ortho-to-para ratio is quite variable, typically falling substantially below the equilibrium value of 3 attained at the measured gas temperatures. The non-equilibrium ortho-to-para ratios are characteristic of temperatures as low as ~ 50 K, and are a remnant of an earlier epoch, before the gas temperature was elevated by the passage of a shock. Correlations between the gas temperature and H2 ortho-to-para ratio show that ortho-to-para ratios < 0.8 are attained only at gas temperatures below ~ 900 K; this behavior is consistent with theoretical models in which the conversion of para- to ortho-H2 behind the shock is driven by reactive collisions with atomic hydrogen, a process which possesses a substantial activation energy barrier (E_A/k ~ 4000 K) and is therefore very inefficient at low temperature.Comment: 45 pages, including 16 figures. Accepted for publication in Ap