Search NASA⌕ Search
Home/Archive/NASA NTRS

NASA NTRS · 20210010388

The International Pulsar Timing Array: Second Data Release

B B P Perara·M E DeCesar·P B Demorest·M Kerr·L Lentati·D J Nice·S Oslowski·S M Ransom·M J Keith·Z Arzoumanian·M Bailes·P T Baker·C G Bassa·NDR Bhat·A Brazier·M Burgay·S Burke-Spolaor·R N Caballero·D J Champion·S Chatterjee·S Chen·I Cognard·J M Cordes·K Crowter·S Dai·G Desvignes·T Dolch·R D Ferdman·E C Ferrara·E Fonseca·J M Goldstein·E Graikou·L Guillemot·J S Hazboun·G Hobbs·H Hu·K Islo·G H Janssen·R Karuppusam·M Kramer·M T Lam·K J Lee·K Liu·J Luo·A G Lyne·R N Manchester·J W McKee·M A McLaughlin·C M F Mingarelli·A P Parthasarathy·T T Pennucci·D Perrodin·A Possenti·D J Reardon·C J Russell·S A Sanidas·A Sesana·G Shaifullah·R M Shannon·X Siemens·J Simon·R Spiewak·I H Stairs·B W Stappers·J K Swiggum·S R Taylor·G Theureau·C Tiburzi·M Vallisneri·A Vecchio·J B Wang·S B Zhang·L Zhang·W W Zhu·X J Zhu
View original source ↗Export metadata ↓

Abstract

In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. We analyse and where possible combine high-precision timing data for 65 millisecond pulsars which are regularly observed by these groups. A basic noise analysis, including the processes which are both correlated and uncorrelated in time, provides noise models and timing ephemerides for the pulsars. We find that the timing precisions of pulsars are generally improved compared to the previous data release, mainly due to the addition of new data in the combination. The main purpose of this work is to create the most up-to-date IPTA data release. These data are publicly available for searches for low-frequency gravitational waves and other pulsar science.

Explore related subjects

neutronpulsarsgravitational wavesdata analysis

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B B P Perara, M E DeCesar, P B Demorest, M Kerr, L Lentati, D J Nice, S Oslowski, S M Ransom, M J Keith, Z Arzoumanian, M Bailes, P T Baker, C G Bassa, NDR Bhat, A Brazier, M Burgay, S Burke-Spolaor, R N Caballero, D J Champion, S Chatterjee, S Chen, I Cognard, J M Cordes, K Crowter, S Dai, G Desvignes, T Dolch, R D Ferdman, E C Ferrara, E Fonseca, J M Goldstein, E Graikou, L Guillemot, J S Hazboun, G Hobbs, H Hu, K Islo, G H Janssen, R Karuppusam, M Kramer, M T Lam, K J Lee, K Liu, J Luo, A G Lyne, R N Manchester, J W McKee, M A McLaughlin, C M F Mingarelli, A P Parthasarathy, T T Pennucci, D Perrodin, A Possenti, D J Reardon, C J Russell, S A Sanidas, A Sesana, G Shaifullah, R M Shannon, X Siemens, J Simon, R Spiewak, I H Stairs, B W Stappers, J K Swiggum, S R Taylor, G Theureau, C Tiburzi, M Vallisneri, A Vecchio, J B Wang, S B Zhang, L Zhang, W W Zhu, X J Zhu. 2019-10-12. The International Pulsar Timing Array: Second Data Release. https://ntrs.nasa.gov/citations/20210010388

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

NASA NTRS2021

Electrolytic Co-deposition Neutron Production Evaluation

Co-deposition electrochemical cells are a simple means to examine novel nuclear reactions. In this study, palladium and deuterium atoms were co-deposited on a cathode at stoichiometric densities, forming dendritic morphologies. Bubble detector neutron dosimeters were used to measure equivalent dose levels during electrolytic deposition. Standard configuration cells expected to produce excess neutrons were denoted as experimental cells and contained an electrolyte consisting of palladium(II) chloride, lithium chloride, and heavy water. The control cells used copper(II) chloride, lithium chloride, and heavy water electrolyte. Experimental and control cells were supplied current, increasing from 0.1 to 100.0 mA over a period of 20 days. For test days 9 through 20, the standard configuration experimental cells exhibited significantly higher average neutron radiation than the controls at a 99% confidence level. Alternative configurations involving more increasing current over a shortened time scale, substitutions of water in place of heavy water or potassium chloride for lithium chloride, as well as inclusion of depleted uranium near the cell cathodes all resulted in inconclusive evidence for promoting neutron production.

neutron↗
NASA NTRS2012

High Spatial Resolution Studies of Epithermal Neutron Emission from the Lunar Poles: Constraints on Hydrogen Mobility

The data from the collimated sensors of the LEND instrument are shown to be of exceptionally high quality. Counting uncertainties are about 0.3% relative and are shown to be the only significant source of random error, thus conclusions based on small differences in count rates are valid. By comparison with the topography of Shoemaker crater, the spatial resolution of the instrument is shown to be consistent with the design value of 5 km for the radius of the circle over which half the counts from the lunar surface would be determined. The observed epithermal-neutron suppression factor due to the hydrogen deposit in Shoemaker crater of 0.25 plus or minus 0.04 cps is consistent with the collimated field-of-view rate of 1.7 cps estimated by Mitrofanov et al. (2010a). The statistical significance of the neutron suppressed regions (NSRs) relative to the larger surrounding polar region is demonstrated, and it is shown that they are not closely related to the permanently shadowed regions. There is a significant increase in H content in the polar regions independent of the H content of the NSRs. The non-NSR H content increases directly with latitude, and the rate of increase is virtually identical at both poles. There is little or no increase with latitude outside the polar region. Various mechanisms to explain this steep increase in the non-NSR polar H with latitude are investigated, and it is suggested that thermal volatilization is responsible for the increase because it is minimized at the low surface temperatures close to the poles.

neutron↗