The first deep X-ray and optical observations of the closest isolated radio pulsar

With a distance of 170 pc, PSR J2144-3933 is the closest isolated radio pulsar currently known. It is also the slowest and least energetic radio pulsar; indeed, its radio emission is difficult to account for with standard pulsar models, since its position in the P-Pdot diagram is far beyond typical "death lines". Here we present the first deep X-ray and optical observations of PSR J2144-3933, performed in 2009 with XMM-Newton and the VLT, from which we can set one of the most robust upper limits on the surface temperature of a neutron star. We have also explored the possibility of measuring the neutron star mass from the gravitational lensing effect on a background optical source.Comment: 4 pages, 3 figures; to appear in the Proceedings of the Pulsar Conference 2010, Chia, Sardinia (Italy), 10-15 October 201

Constraining the optical emission from the double pulsar system J0737-3039

We present the first optical observations of the unique system J0737-3039 (composed of two pulsars, hereafter PSR-A and PSR-B). Ultra-deep optical observations, performed with the High Resolution Camera of the Advanced Camera for Surveys on board the Hubble Space Telescope could not detect any optical emission from the system down to m_F435W=27.0 and m_F606W=28.3. The estimated optical flux limits are used to constrain the three-component (two thermal and one non-thermal) model recently proposed to reproduce the XMM-Newton X-ray spectrum. They suggest the presence of a break at low energies in the non-thermal power law component of PSR-A and are compatible with the expected black-body emission from the PSR-B surface. The corresponding efficiency of the optical emission from PSR-A's magnetosphere would be comparable to that of other Myr-old pulsars, thus suggesting that this parameter may not dramatically evolve over a time-scale of a few Myr.Comment: 16 pages, 3 figures, ApJ accepte

Detection of continuum radio emission associated with Geminga

A deep Very Large Array observation of the Geminga pulsar field led to the discovery, at a higher than 10 sigma significance level, of radio emission trailing the neutron star proper motion. This 10-arcsec-long radio feature, detected with a flux of 0.4 mJy at 4.8 GHz, is marginally displaced (2.7\pm1.8 arcsec) from the pulsar (which, at any rate, is unlikely to contribute with magnetospheric pulsed emission more than 15% to the total observed radio luminosity, about 1E26 erg/s) and positionally coincident with the X-ray axial tail recently discovered by Chandra and ascribed to the pulsar wind nebula (PWN). Overall, the Geminga radio tail is compatible with the scenario of a synchrotron-emitting PWN, but the present data do not allow us to discriminate between different (and not always necessarily mutually exclusive) possible processes for producing that. If this radio feature does not result from intrinsic peculiarities of Geminga, but its proximity and radio-quiet nature (both helping in not hindering the faint diffuse radio emission), other relatively near and energetic radio-quiet pulsars could show similar structures in dedicated interferometric observations.Comment: Version accepted by MNRAS Letters (new title and substantial changes in response to referees reports); 5 pages, 2 colour figure

2nd CapHaz-Net Regional Hazard Workshop: Social capacity building for Alpine hazards

The Alpine Space is a trans-national territory inhabited by 13 million people and comprising the territory of 8 countries, 83 regions and about 6,200 communities. It is characterised by a great variety in terms of natural hazard exposure. Floods, avalanches, debris flows, landslides, forest fires threaten the entire Alpine Space and are triggered by both natural and anthropogenic factors. The work described in this report focuses on this space and aims at bringing together and confronting different perspectives on the theme of social capacity building. It summarises the results of one of the work packages (WP8) of the CapHaz-Net project, which aims at identifying social capacities that contribute to making European societies more resilient to the impacts of natural hazards. More precisely the work presented here links previous project findings (related both to central topics and specific social capacities) to the practice of alpine hazards management in Europe, underlining potentials for enhancement of resilience both in this region and in Europe as a whole. This report is based on the preparatory work and the results of the Alpine Regional Hazard Workshop that took place in Gorizia (North Eastern Italy) on 4th and 5th April 2011. The main objectives were to provide an overview of existing institutional frames and the respective policy context at the regional scale, to better understand how social capacity building and preparedness strategies for Alpine hazards work in practice and to foster interdisciplinary and cross country dialogue between scientists and practitioners. This was done by taking into account strengths and weaknesses of existing tools and approaches and by analysing the potential for transferring best practices to different regional and hazard contexts. To bridge the gap between research and practice both theoretical knowledge and practical experiences were taken into account. The workshop started from a description of the main characteristics of alpine hazards. Then the focus shifted on operational risk management in four different countries of the alpine arch (Austria, Switzerland, Slovenia and Italy) and finally on practices for risk mitigation in two Italian case studies (Vipiteno/Sterzing in the Trentino Alto Adige region and Malborghetto-Valbruna in the Friuli Venezia Giulia region). The SWOT methodology was used as a heuristic tool for organizing the available insights and the participants' discussion. Natural sciences, historical perspectives as well as legal analysis have contributed to broadening and detailing the social capacity concept and more precisely to characterising and further specifying each particular capacity. Practitioners in the field of alpine hazards in different countries and residents of the two case study area also contributed by presenting and discussing their views and perspectives about prevention, mitigation, emergency management and recovery from natural disasters