04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

30-03-2011
Evidence of red giants with a hydrogen burning shell

Thanks to the data of the NASA  Kepler satellite, an international team including Rafael Garcia of the Astrophysical Department at CEA-Irfu [1], succesfully probe the heart of hundreds of giant stars for the first time. The researchers used stellar seismology to analyze very small oscillations in surface brightness to infer the characteristics of the heart of the stars. In the large sample studied, they have managed to distinguish where the nuclear fusion reactions take place, in the core of the stars or in a surrounding shell. This is a major discovery for the understanding of the stars because so far nothing helped the astronomers to isolate these evolutionary stages corresponding to a different stage in the life of a star. The results are published in the journal Nature of March 31, 2011.

 

The concert of red giants (mp3) Listen to the vibrations of giant stars translated into audible sounds according to their actual frequencies: listen to three stars of increasing size [1'00],

Crédits Daniel Huber (Univ. Sydney 2011)

17-03-2011
First detection of gravity-like waves in a red giant star

Waves traveling inside the core of a giant star have been discovered by a international team of researchers including Rafael A. Garcia, member of the Service d'Astrophysique of CEA-Irfu [1]. The results were obtained using 320-day observations  of the Kepler satellite by means of stellar seismology. These waves, known as gravity modes, produce very small changes in the brightness at the surface of the star. The vibrations of the star offer the possibility of measuring the density, chemical composition, and the internal rotation of the star otherwise inaccessible. So far, these waves could only be unveiled for the Sun. The Sun will become a red giant in about 6 billion years. This discovery thus provides a crucial diagnosis on the future of our star. These results are published in Science- magazine on March 17, 2011.

14-03-2011

 

 

“The research teams are really enthusiastic about what they do and it was fantastic listening to them. The event provided an excellent opportunity to meet them”

  said one participant at the Master's Day held at the end of January.

 

 

 

 

04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

29-01-2011
Clusters and superclusters billions of light-years away

An international team, including scientists from the Astrophysics Department-AIM and the Particle Physics Department of CEA-Irfu, has just used the Planck satellite to discover galaxy clusters with characteristics that were previously unknown. These clusters, which contain up to a thousand galaxies, are the largest structures in the Universe. Many of them are located very far away from us, and we still know relatively little about them. Astrophysicists were able to detect the new clusters thanks to the imprint left in the background radiation of the universe by the hot gas from the clusters. Of the 189 clusters detected by Planck at distances from 1 to 5 billion light-years, 20 were previously unknown. Thanks to a joint program with the XMMNewton x-ray satellite, some of these new clusters could be observed, revealing weaker luminosity and a highly perturbed gas distribution. These must therefore be clusters with different characteristics.
These results were presented at a scientific colloquium on results from the Planck satellite, held from 10th to 14th January 2011 in Paris. They were published in a special issue of Astronomy & Astrophysics.

For a more detailed account, see also the French version.

14-01-2011

The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris).


Read the joint press release from CNES, CNRS, CEA, and ESA


Also refer to the program of the colloquium

 

 

 

Contact:

 

J. Bonnet-bidaud

12-01-2011

 

The Sloan Digital Sky Survey III, a collaboration with contributions from researchers at the CNRS and CEA, has just released the widest sky survey ever carried out to the international scientific community at the annual meeting of the American Astronomy Society held in Seattle between January 10 and 13, 2011. This survey provides an image and a catalog of sources covering almost all of the sky in five colors and with a quality never before achieved in terms of the sky coverage and the accuracy of the luminosity measurements. The catalog, containing around 470 million objects (galaxies, stars, quasars, etc.), will be published in the Astrophysical Journal Supplements.

30-03-2011
Evidence of red giants with a hydrogen burning shell

Thanks to the data of the NASA  Kepler satellite, an international team including Rafael Garcia of the Astrophysical Department at CEA-Irfu [1], succesfully probe the heart of hundreds of giant stars for the first time. The researchers used stellar seismology to analyze very small oscillations in surface brightness to infer the characteristics of the heart of the stars. In the large sample studied, they have managed to distinguish where the nuclear fusion reactions take place, in the core of the stars or in a surrounding shell. This is a major discovery for the understanding of the stars because so far nothing helped the astronomers to isolate these evolutionary stages corresponding to a different stage in the life of a star. The results are published in the journal Nature of March 31, 2011.

 

The concert of red giants (mp3) Listen to the vibrations of giant stars translated into audible sounds according to their actual frequencies: listen to three stars of increasing size [1'00],

Crédits Daniel Huber (Univ. Sydney 2011)

17-03-2011
First detection of gravity-like waves in a red giant star

Waves traveling inside the core of a giant star have been discovered by a international team of researchers including Rafael A. Garcia, member of the Service d'Astrophysique of CEA-Irfu [1]. The results were obtained using 320-day observations  of the Kepler satellite by means of stellar seismology. These waves, known as gravity modes, produce very small changes in the brightness at the surface of the star. The vibrations of the star offer the possibility of measuring the density, chemical composition, and the internal rotation of the star otherwise inaccessible. So far, these waves could only be unveiled for the Sun. The Sun will become a red giant in about 6 billion years. This discovery thus provides a crucial diagnosis on the future of our star. These results are published in Science- magazine on March 17, 2011.

29-01-2011
Clusters and superclusters billions of light-years away

An international team, including scientists from the Astrophysics Department-AIM and the Particle Physics Department of CEA-Irfu, has just used the Planck satellite to discover galaxy clusters with characteristics that were previously unknown. These clusters, which contain up to a thousand galaxies, are the largest structures in the Universe. Many of them are located very far away from us, and we still know relatively little about them. Astrophysicists were able to detect the new clusters thanks to the imprint left in the background radiation of the universe by the hot gas from the clusters. Of the 189 clusters detected by Planck at distances from 1 to 5 billion light-years, 20 were previously unknown. Thanks to a joint program with the XMMNewton x-ray satellite, some of these new clusters could be observed, revealing weaker luminosity and a highly perturbed gas distribution. These must therefore be clusters with different characteristics.
These results were presented at a scientific colloquium on results from the Planck satellite, held from 10th to 14th January 2011 in Paris. They were published in a special issue of Astronomy & Astrophysics.

For a more detailed account, see also the French version.

14-01-2011

The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris).


Read the joint press release from CNES, CNRS, CEA, and ESA


Also refer to the program of the colloquium

 

 

 

Contact:

 

J. Bonnet-bidaud

04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

29-01-2011
Clusters and superclusters billions of light-years away

An international team, including scientists from the Astrophysics Department-AIM and the Particle Physics Department of CEA-Irfu, has just used the Planck satellite to discover galaxy clusters with characteristics that were previously unknown. These clusters, which contain up to a thousand galaxies, are the largest structures in the Universe. Many of them are located very far away from us, and we still know relatively little about them. Astrophysicists were able to detect the new clusters thanks to the imprint left in the background radiation of the universe by the hot gas from the clusters. Of the 189 clusters detected by Planck at distances from 1 to 5 billion light-years, 20 were previously unknown. Thanks to a joint program with the XMMNewton x-ray satellite, some of these new clusters could be observed, revealing weaker luminosity and a highly perturbed gas distribution. These must therefore be clusters with different characteristics.
These results were presented at a scientific colloquium on results from the Planck satellite, held from 10th to 14th January 2011 in Paris. They were published in a special issue of Astronomy & Astrophysics.

For a more detailed account, see also the French version.

14-01-2011

The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris).


Read the joint press release from CNES, CNRS, CEA, and ESA


Also refer to the program of the colloquium

 

 

 

Contact:

 

J. Bonnet-bidaud

04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

29-01-2011
Clusters and superclusters billions of light-years away

An international team, including scientists from the Astrophysics Department-AIM and the Particle Physics Department of CEA-Irfu, has just used the Planck satellite to discover galaxy clusters with characteristics that were previously unknown. These clusters, which contain up to a thousand galaxies, are the largest structures in the Universe. Many of them are located very far away from us, and we still know relatively little about them. Astrophysicists were able to detect the new clusters thanks to the imprint left in the background radiation of the universe by the hot gas from the clusters. Of the 189 clusters detected by Planck at distances from 1 to 5 billion light-years, 20 were previously unknown. Thanks to a joint program with the XMMNewton x-ray satellite, some of these new clusters could be observed, revealing weaker luminosity and a highly perturbed gas distribution. These must therefore be clusters with different characteristics.
These results were presented at a scientific colloquium on results from the Planck satellite, held from 10th to 14th January 2011 in Paris. They were published in a special issue of Astronomy & Astrophysics.

For a more detailed account, see also the French version.

14-01-2011

The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris).


Read the joint press release from CNES, CNRS, CEA, and ESA


Also refer to the program of the colloquium

 

 

 

Contact:

 

J. Bonnet-bidaud

12-01-2011

 

The Sloan Digital Sky Survey III, a collaboration with contributions from researchers at the CNRS and CEA, has just released the widest sky survey ever carried out to the international scientific community at the annual meeting of the American Astronomy Society held in Seattle between January 10 and 13, 2011. This survey provides an image and a catalog of sources covering almost all of the sky in five colors and with a quality never before achieved in terms of the sky coverage and the accuracy of the luminosity measurements. The catalog, containing around 470 million objects (galaxies, stars, quasars, etc.), will be published in the Astrophysical Journal Supplements.

04-03-2011

IRFU's Double Chooz group has just published some surprising results regarding the flux of antineutrinos generated by uranium and plutonium fission products in nuclear power reactors. A more precise estimate of this flux has revealed a +3% shift with respect to the predictions considered as the benchmark for the past 25 years. The re-analysis of the most important past reactor neutrino experimental results, in the light of this new flux prediction, lead to the so called 'reactor antineutrino anomaly'. Including other effects such as the evolution of the neutron lifetime and the presence of long-lived fission isotopes, the averaged shortfall in the number of antineutrinos detected at short baseline reactor experiments is almost 6%. The hypothesis according to which this anomaly can be explained by the existence of a new particle, a 4th "sterile” neutrino, ties in surprisingly well with other independent results. 
 
If its existence is proven by forthcoming experiments this 4th neutrino, interacting only with gravity, should be added to the bestiary of the Standard Model of particle physics. It could have some impact on cosmology as well. Nonetheless, neutrino flux measurements will have to be performed less than ten meters from reactor cores to obtain irrefutable proof that the new particle exists. This is within the grasp of present-day techniques used in neutrino detection experiments, particularly in the case of Nucifer, a detector that is about to be used in a data-gathering mission on Osiris, the research reactor in Saclay. Other new proposals are being discussed by the particle physics community to test this anomaly, with new neutrino beam experiment (at CERN) or by deploying a Mci neutrino generator in large liquid scintillator detectors (like Borexino).

 

Retour en haut