The Deadly Spider Has Been Found !

474230main_Pulsar_Binary_Mod_1A few days ago (Feb. 5th) I wrote a post about a special source, named XSS J12270-4859, a cryptic name behind a binary system composed by a neutron star and a normal companion star slightly less massive than our Sun. Continue reading


A Deadly Spider in Disguise

A pulsar located about 5,000 light years from Earth.

My colleagues and I have recently studied a new peculiar binary system (XSS J12270-4859) formed by a neutron star and a low mass star that can be found in the constellation Centaurus, in the southern hemisphere. Our recent work, lead by Cees Bassa from ASTRON, can be found online at this link. Continue reading

The Missing Link


(Update: one paper is now published

Today I’d like to  tell a brief story and discuss three recent papers accepted or submitted to The Astrophysical Journal & The Astrophysical Journal Letters (and make some self-promotion as I’ve been involved in writing two such papers). The story is about an extraordinary object, called PSR J1023+0038, or the “Missing Link Binary Pulsar”, and the three papers I’d like to talk about are recent works on this pulsar.

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Is There Anybody Out There ?

pulse-trainHow many times have we heard the question “are we alone in the Universe” ? Does life exist somewhere else ? Does intelligent life exist ? There’s no need to introduce the topic, as countless discussions have been made through the centuries . Still this question remains one of the most (if not the most) fascinating ones about the Universe and astronomers have spent some efforts in the past decades trying to at least narrow down the possibilities.
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Quantum Vortices in the Sky

vortex21Turbulence is a common chaotic phenomenon that everyone has certainly experienced: you witness the development of turbulence when you stir a coffee too vigorously or watch the smoke of a cigarette or feel the aeroplane going up and down. What makes turbulence often spectacular is the presence of several vortices which are indeed seen in many atmospheric phenomena from the magnificent tornadoes and hurricanes to the tiny dust devils. Such vortices have a certain life-time that is set by the amount of energy that sustains them and that works against viscosity, which tries to re-establish the calm and quietness of the flow.

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A New Millisecond Pulsar Catalogue

800px-Pulsar_schematic.svgTriggered by an idea of J. Hessel while I was working at ASTRON, I decided to create a new pulsar catalogue that includes all radio, gamma and accreting millisecond pulsars known. The list is updated but of course omissions and mistakes are certainly possible. So please if you notice a mistake submit a correction by using the contact form on the pulsar catalogue webpage.

This catalogue has been compiled by merging the information of three different catalogues already present on the web (P. Freire, D. Lorimer and the ATNF Catalogue) and by integrating it with red-backs, black-widows (thanks Mallory Roberts !) and accreting millisecond pulsars parameters taken from two different papers. Links to the resources can be found on the pulsar catalogue page.

I hope you will find it useful. If you’d like to see different fields in the table please let me know. Go now to the pulsar catalogue !

Some Free Codes for Top Research in Astronomy

mhdI am mostly an observer working in the field of high energy astrophysics, doing experiments and performing observations with space and ground based telescopes. However, once in a while I also like very much to use numerical codes to solve complex physical problems that require large computational resources. So I would like to share the numerical codes that I’ve used throughout my career and that I found exceptionally useful and easy to use.

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