NATIONAL INSTITUTE FOR ASTROPHYSICS
Cagliari Astronomical Observatory
Località Poggio dei Pini
Strada 54
I-09012 Capoterra(CA), Italy

Record of my many trips to Australia

General information

Personal data

• Nicolò D'Amico (Nichi)
• Was born in Palermo on June the 28th, 1953
• Married with Adriana Di Salvo, psychotherapist
• One daughter, Giulia, a promising drama writer

Present position

• Chair Professor of Astrophysics at the Faculty of Science of the Cagliari University
• Director of the Sardinia Radio Telescope project

  Professional interests

• Radio astronomy
• Neutron Stars
• Gravitation
• High Energy Astrophysics

  Foreign languages

• English (fluent)
• French (scholastic)

  Office Address

c/o Osservatorio Astronomico di Cagliari
Loc. Poggio dei Pini, Strada 54
09012 Capoterra (CA)

Email: damico@oa-cagliari.inaf.it
Home Page: http://pulsar.ca.astro.it/pulsar/personal/NichiDAmico/
Tel. +39 070 711 80 208
Mobile: +39 329 660 3828

 

Academic Record

• 1977 - Laurea in Physics cum laude, awarded at the University of Palermo, under the supervision of Prof. Livio Scarsi
• 1978 - One year Regional fellowship CRRN/SM, assigned to the Chair of Advanced Physics (Chair Prof. Livio Scarsi)
• 1979/1981 - Three years CNR Fellowship, assigned to the Chair of Advanced Physics (Chair Prof. Livio Scarsi), interrupted for fifteen months for the military duty
• 1981/1995 - Research assistant of General Physics at the Faculty of Science of the Palermo University, and Associated to the GIFCO Research Unit "High Energy Astrophysics"
• 1985 - On leave for one year with a NATO Fellowship, in Sydney, at CSIRO Radio Physics Division
• 1988/2001 - Associated to the Radio Astronomy Institute of CNR, in Bologna
• 1996/2001 - Senior Astronomer at the Bologna Astronomical Observatory
• Since 2002 - Chair Professor of Astrophysics at the Faculty of Science of the Cagliari University
• Since 2002 - Director of the Cagliari Astronomical Observatory
• Since 2006 - Director of the Sardinia Radio Telescope project

Awards

• 1993 - Melbourne - CSIRO Medal Certificate, as member of the PULSAR TEAM, for "the discovery and interpretation of pulsars"
• 2005 - Palermo - Targa Piazzi for "the research in astronomy"
• 2005 - London - Descartes Prize, as member of the PULSE Collaboration for "demonstrating the impact of European pulsar science on modern physics"

Details and pictures can be found following the Awards link on the main home page.

Breaking results

Several scientific results, obtained in the context of the various pulsar search experiments carried out at Parkes, can be classified as "breaking results" in the sense they where quoted in the cover page of high impact factors journals, such as Nature or Science, they were the subject of authoritative citations in the hot topics sections of the same journals, or they were highly cited. Here we list the main breaking results, whose details can be found in the Publications link of the home page, which includes about 250 entries, and following the ISI-Thomson link on the same main home page.

• Quotation on the Nature cover page (1990, 347, 650) of the discovery of the eclipsing millisecond pulsar in Terzan 5.
• Entire Nature cover page (1991, 352, 219) dedicated to the discovery of ten millisecond pulsar in 47 Tucanae.
• Quotation on the Nature cover page (2003, 426, 531) of the discovery of the highly relativistic binary pulsar PSR 0737-3039, and authoritative citation by Van den Heuvel on the News & Views section of the same Nature issue.
• The above paper is classified as a Fast Breaking Paper by the ISI-Thomson Institute, as it is reported on their site.
• Entire Science cover page (2004, 303, 1153) dedicated to the discovery of the pulsar companion to PSR 0737-3039, which then turned out to be the first ever known double pulsar.
• The above paper is classified by Science as one of the first top ten breaking results of year 2004.
  

Press releases and Media citations

Many scientific results obtained in the context of the pulsar search experiments at Parkers and in the collaboration with pulsar timing network of the CGRO satellite, were the subject of international press releases. Details of the various press releases, various citations reported on the media, and some interview can be found in the Press room link of the main home page.

Scientific Activity

Here you find an introduction of the circumstances and motivations which determined the main periods of my scientific career. A summary of the main scientific highlights can be found in the Research link of the main home page.

• The first period: Pulsar observations with the COS-B gamma ray satellite (1977-1981). This period represents the beginning of my scientific activity. I carried out my thesis project in the High Energy Astrophysics group led by Livio Scarsi, in Palermo. The group was involved in the COS-B gamma ray mission, and this circumstance gave me the opportunity to spend quite a bit of time in Saclay (France), and in the other Institutes of the so called COS-B Caravane Collaboration. Because the angular resolution of gamma-ray telescopes is intrinsically poor, a suitable method to separate the contribution of point sources from the Galactic gamma-ray background is timing. In this context, pulsars play a major role, as their timing pattern can be perfectly determined at radio wavelengths and used to fold the gamma-ray data, and this is particularly useful when a rather low photon-counting statistics is available as in gamma-ray astronomy. In fact, the only known point sources at gamma-ray wavelengths at that epoch were the Crab and Vela pulsar. In this period, I have been mostly involved in the attempt to detect gamma-ray pulsations from other known radio pulsars using the data collected with the COS-B satellite. In the context of this project, in June 1979 I visited Dick Manchester at CSIRO Radiophysics, in Sydney, in order to collect updated ephemeris of a sample of radio pulsars. That visit and my first trip to Parkes were fundamental for me to switch to radio astronomy.

• Opening high frequency pulsar search experiments at Parkes and Molonglo (1981-1986). Though in gamma-ray astronomy it is difficult to strictly classify point sources, the Caravane Collaboration managed to classify a number of localised sources of gamma-ray radiation, mostly along the Galactic plane. In 1981, I discussed with Dick Manchester the possibility to use the Parkes radio telescope to search such gamma-ray error boxes for radio pulsars similar to the Crab and Vela pulsar. Because the previous pulsar surveys at radio wavelengths were carried out at relatively low frequency (typically 400 MHz), they were not very sensitive to pulsars located at low Galactic latitudes, because of dispersion and interstellar scattering. So, the case for undertaking a major pulsar survey of the Galactic plane at relatively high frequencies was rather strong. However, because the telescope beams at high frequencies are relatively narrow, a survey of the entire Galactic plane was a major task, so a pulsar search of the potential indicators of the presence of a missing pulsar, such as Supernova Remnants, localised gamma ray sources, and steep spectrum radio sources, was the right way to begin. I offered my self to get involved in the construction and commissioning of pulsar back-ends and software packages, and I established a fruitful collaboration with Dick. This period represents a sort of pioneered era based on pilot searches of unexplored portions of the pulsar parameters space. We searched several gamma rays sources error box, SNR, steep spectrum radio sources at Parkes at 1.4 GHz and at Molonglo at 843 MHz. After the discovery of the original millisecond pulsar made at Arecibo by Shri Kulkarni and Don Baker, we also begin to devote some effort to this intriguing zone of the pulsar parameters space, using in the beginning the E-W arm of the Molonglo Cross at 843 MHz, and a pulsar back-end developed by John Durdin. Indeed, at Molonglo we searched a limited strip of the Galactic plane for millisecond pulsars. Later, it became clear that in spite of the location of the original millisecond pulsar, such objects might be more abundant and more easily detectable at high latitudes. Among the various interesting results achieved in this period, we should not forget a couple of strong headache, like the aliased detection at Parkes of the (still unknown) original millisecond pulsar, and some statistical artifacts of the Molonglo data, suggestive of a binary millisecond pulsar with an orbital period of ten minutes or so.

• Systematic pulsar search experiments at Parkes (1987-1996). The pilot searches carried out at Parkes and Molonglo proved that an observing frequency around 1.4 GHz is ideal for the detection of highly dispersed short period pulsars, especially at low Galactic latitudes, where young pulsars are usually located. At the same time, at Jodrell Bank Clifton and Lyne by searching a strip of the Galactic plane at 1.4 GHz, found several new pulsars, mostly relatively young and energetic. So, it was time to undertake a major survey of the southern Galactic plane. In May 1987, in a meeting at Jodrell Bank, Andrew Lyne, Dick Manchester and myself decided to join the effort, and designed a deep survey of the Galactic plane at 1.4 GHz to be carried out at Parkes. A double back-end was constructed at Jodrell and shipped to Parkes, which provided 2 x 64 x 5MHz filters sampled at 2 ms, and 2 x 80 x 1MHz filters sampled at 0.3 ms. With such a system, we have carried out several pulsar search experiments, including a fruitful survey of a strip of the Galactic plane, and many targeted searches. Following the discovery at Jodrell Bank of a millisecond pulsar in the Globular Cluster M28, which required rather long integrations and the use of supercomputing facilities, I developed a new version of our search code, called VLSA (Very Long Spectral Analysis), in order to coherently process time series up to 32 Million samples, a task which was not straightforward for the standard computing facilities available at that epoch. Having such a code available, we started a deep search of the Globular Cluster system, pushing long integrations, and we discovered many interesting millisecond pulsars, including ten millisecond pulsars in 47 Tucanae. In 1990, the discovery by Alex Wolszcang at Arecibo of a millisecond pulsar at high Galactic latitude, proved that in spite of the location of the original millisecond pulsar, such objects might be abundant at high latitudes. This switched our interests back to the use low frequencies. In fact, at high Galactic latitudes the effect of dispersion and interstellar scattering is negligible, so millisecond pulsar can be easily detected, the telescope beams are relatively large so large portions of sky can be quickly searched, and the fluxes of such steep spectrum sources are relatively high. So, we designed a full sky survey to be carried out at Parkes, at 430 MHz, using 2 x 128 x 125kHz filters sampled at 0.3 ms, which were constructed at Jodrell Bank and Bologna, and we discovered more that 100 new pulsars, including 17 new millisecond pulsars. During this period, the pulsar team at Parkes has been growing significantly, as we hosted PhD students and Post-docs from several countries, like Matthew Bailes, Simon Johnston, Luciano Nicastro (Luch), Duncan Lorimer (Dunc), Vicky Kaspi, and many others.

• Pulsar experiments with the Northern Cross Radiotelescope and the first submillisecond pulsar search (1988-1995). The Italian Northern Cross radiotelescope, located in Medicina, about 30 km from Bologna, in Italy, is potentially an ideal instrument for pulsar surveys, because it has a huge collecting area (about 35,000 square meters), and when I first visited the site I was fascinated by this instrument. Indeed, thanks to Gavril Grueff, Giuseppe Roffi and Mario Vigotti, the Cross provided interesting follow-up observations of pulsars, soon after the original discovery made by Jocelyn Bell and Antony Hewish at Cambridge. When I first discussed with Gavril and with the site Officer, Stelio Montebugnoli, the possibility to use the E-W arm of the Cross (which operates at 408 MHz) for pulsar observations, we realised that a serious upgrade was needed. At that epoch, the signals of the 1536 E-W arm dipoles were summed in a tree fashion scheme, and fed into 6 receivers. The loss occurring in the summing network resulted in a system temperature of more that 400 °K, so in spite of the relatively high antenna gain (about 2.5 °K/Jy), the instantaneous sensitivity was not very high. With the help of Goliardo Tomassetti and Claudio Bortolotti, we managed to install 12 low noise preamplifiers, close to the dipole lines but still feeding the existing 6 receivers, which resulted in a system temperature of 120 °K, so a system noise equivalent flux density of about 45 Jy. Then, with the help of Gavril and Mauro Roma, we arranged phase rotators to sum the 6 individual IF channels in such a way that we could track a source for about 2 min. Also, Stelio and Claudio arranged new IF channels providing a 4 MHz bandwidth, in spite of the existing 2 MHz. With these figures, the E-W arm had enough sensitivity to detect with good S/N a significant fraction of the known pulsars. So we could initiate a pulsar timing program, which became part of the international timing effort to the CGRO gamma-ray mission. At this stage, the main issue was then the use of this instrument for a survey. You can easily realise that with the figures available, no "normal" new pulsars were expected to be found in an all sky survey, unless we could keep the sensitivity level in the millisecond period range, which at that epoch was still poorly explored. So, with the help of Stelio, Claudio, Andrea Maccaferri and Claudio Cattani, we constructed a back-end based on 128 x 32KHz filters which we could sample at 64 microseconds. You should realise that which such a system we could easily detect the original millisecond pulsar with a S/N larger that 100 in an unbiased search! At that epoch, apart from some Arecibo strip surveys which were about to begin, no other large scale surveys had the capability to detect the original millisecond pulsar with such high S/N. In turn, because our sensitivity was rather flat down to periods of a fraction of a millisecond, we could attempt to understand the limiting spin period of Neutron Stars, and so probe the equation of state of ultra dense matter. We managed to search about 80% of the Declination range 4° < Dec < 42°, resulting in the discovery of a single millisecond pulsar PSR J0030+0600, having a period of 4.86 ms. In spite of the unprecedented sensitivity in the submillisecond period range, no ultra-fast pulsars were found, a result which was not contradicted so far. With the advent of the SKA concept, and with the need to have available in Europe a suitable test-bed for SKA, Stelio and the Medicina technical staff are now providing low noise receivers everywhere up in the Cross, which would eventually results in many thousands beams available. So, I trust that the pulsar epoch for the Northern Cross is not over yet!
  

• The Parkes multibeam surveys and the foundation of the Italian Pulsar Group (since 1996). When at ATNF Ron Ekers launched the idea to develop a 21cm multibeam receiver for the Parkes radio telescope, it became clear to Dick, Andrew and myself that this instrument would have been ideal in order to undertake a deep pulsar survey of the Galactic plane. This was indeed a very exciting period of my career. Thanks to several financial grants obtained by the Ministry of Research, I managed to get involved in the hardware development of the new system. Also, in this period (I was still in Bologna at that epoch) I enrolled Andrea Possenti as a PhD student, and few years later Marta Burgay, who played a major role in the discovery of the Double Pulsar, so I founded a research group, and in 2002, we all moved to Cagliari. With these experiments, in a few years we have nearly doubled the number of know pulsars. The success of these experiments is definitely due to the use of the 21cm multibeam receiver at Parkes, and to the implementation of a rather complex suite of backend systems and data processing procedures, several of them developed by our group, first in Bologna and since 2002 in Cagliari. The multibeam receiver operates at a central frequency of 1347 MHz and consists of 13 separate beams. The total 288 MHz bandwidth was subdivided into 96 X 3 MHz channels in order to minimise the pulse broadening due to dispersion in the interstellar medium. The signal was one-bit sampled and recorded on Digital Linear Tapes for off-line analysis. We first used the 21 cm multibeam receiver system and multibeam filter banks, digitizer, and data-acquisition system to survey a region within |b| < 5 degrees in the inner Galactic plane for pulsars, many of which were expected to be young and/or short-period. This survey was a factor of seven more sensitive to young and distant pulsars than that of Johnston et al. (1992) and led to the discovery of about 1000 pulsars. Then we have carried out a high latitude survey which covered the region enclosed by Galactic longitude 220° < l < 260° and Galactic latitude |b| < 60° for a total of 6456 pointings of 265 s duration each. The observations, started in November 2000 and completed in December 2003, were made using the same multibeam receiver and data acquisition system on the Parkes 64-m radio telescope. The processing and inspection of the data of the Parkes High-Latitude Pulsar Survey is now finished (although a re-examination of the oldest results using Reaper is under way) and yielded the discovery of 18 new pulsars, four of which belonging to the class of the rapidly spinning millisecond pulsars. Three of the latter belong to a binary system and one of them, PSR J0737-3039A, orbits around another pulsar, PSR J0737-3039B: this is the first ever Double Pulsar system discovered. We have now in progress a multibeam survey of the Perseus Arm region and a new major survey which exploits the new FPGA technologies to get much more time and frequency resolution.