A5041234116- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Image Retrieval and Classification Techniques
- Astronomical Observations and Instrumentation
- Video Analysis and Summarization
- Stellar, planetary, and galactic studies
- Data Management and Algorithms
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Logic, programming, and type systems
- Distributed systems and fault tolerance
- Semantic Web and Ontologies
- Advanced Image and Video Retrieval Techniques
- History and Developments in Astronomy
- Geomagnetism and Paleomagnetism Studies
- Parallel Computing and Optimization Techniques
- Computational Physics and Python Applications
- High-pressure geophysics and materials
- Seismology and Earthquake Studies
- Geophysics and Sensor Technology
- Business Process Modeling and Analysis
- Security and Verification in Computing
Max Planck Institute for Radio Astronomy
2015-2023
The University of Texas Rio Grande Valley
2016
Max Planck Society
2015
Laboratoire d'informatique de Nantes Atlantique
1999-2012
We describe an ongoing search for pulsars and dispersed pulses of radio emission, such as those from rotating transients (RRATs) fast bursts, at 350 MHz using the Green Bank Telescope. With Ultimate Pulsar Processing Instrument, we record 100 bandwidth divided into 4096 channels every 81.92 μs. This survey will cover entire sky visible to Telescope (δ > −40°, or 82% sky) outside Galactic Plane be sensitive enough detect slow low dispersion measure (<30 pc cm−3) millisecond (MSPs) with a 0.08...
To understand the nature of supernovae and neutron star (NS) formation, as well binary stellar evolution their interactions, it is important to probe distribution NS masses. Until now, all double (DNS) systems have been measured having a mass ratio close unity (q ≥ 0.91). Here, we report measurement individual masses 4.07-day pulsar J0453+1559 from measurements rate advance periastron Shapiro delay: Mp = 1.559 ± 0.005 M⊙ that its companion M⊙; q 0.75. If this also an NS, indicated by orbital...
In the modern era of big data, many fields astronomy are generating huge volumes analysis which can sometimes be limiting factor in research. Fortunately, computer scientists have developed powerful data-mining techniques that applied to various fields. this paper, we present a novel artificial intelligence (AI) program identifies pulsars from recent surveys by using image pattern recognition with deep neural nets—the PICS (Pulsar Image-based Classification System) AI. The AI mimics human...
We provide timing solutions for 45 radio pulsars discovered by the Robert C. Byrd Green Bank Telescope. These were found in North Celestial Cap pulsar survey, an all-GBT-sky survey being carried out at a frequency of 350 MHz. include data from Telescope and Low Frequency Array. Our sample includes five fully recycled millisecond (MSPs, three which are binary system), new relativistic double neutron star system, intermediate mass pulsar, mode-changing 138-ms with very low magnetic field,...
We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover sky declinations -1 to 28 degrees, excluding region within 5 degrees Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. record data 57 MHz bandwidth 1024 channels 125 us sampling time. 60 s transit time through beam means that is sensitive very tight relativistic binaries even no acceleration searches. To date we...
Abstract In this work, we report the discovery and characterization of PSR J1411+2551, a new binary pulsar discovered in Arecibo 327 MHz Drift Pulsar Survey. Our timing observations radio system span period about 2.5 years. This campaign allowed precise measurement its spin (62.4 ms) derivative (9.6 ± 0.7) × 10 −20 s −1 ; from these, derive characteristic age >9.1 Gyr surface magnetic field strength <2.6 9 G. These numbers indicate that was mildly recycled by accretion matter...
ABSTRACT We present Clusterrank, a new algorithm for identifying dispersed astrophysical pulses. Such pulses are commonly detected from Galactic pulsars and rotating radio transients (RRATs), which neutron stars with sporadic emission. More recently, isolated, highly dubbed fast bursts (FRBs) have been identified as the potential signature of an extragalactic cataclysmic source distinct RRATs. Clusterrank helped us discover 14 8 RRATs in data Arecibo 327 MHz Drift Pulsar Survey (AO327). The...
Modern radio pulsar surveys produce a large volume of prospective candidates, the majority which are polluted by human-created frequency interference or other forms noise. Typically, numbers candidates need to be visually inspected in order determine if they real pulsars. This process can labor intensive. In this paper, we introduce an algorithm called PEACE (Pulsar Evaluation Algorithm for Candidate Extraction) improves efficiency identifying signals. The ranks based on score function....
We present 18 pulsar discoveries from the AO327 survey, along with their timing solutions and those for an additional 31 AO327-discovered pulsars. Timing were constructed using observations a follow-up campaign taken between periods of 2013 -- 2019 Arecibo Observatory's 327-MHz receiver. Aside PSR J0916+0658, isolated that shows evidence partial recycling, remaining are non-recycled brief census emission features all pulsars following standouts. PSR~J1942+0142 is found to exhibit very rare...
Low-mass white dwarfs (LMWDs) are believed to be exclusive products of binary evolution, as the Universe is not yet old enough produce them from single stars. Because strong tidal forces operating during interaction phase, remnant host systems observed today expected have negligible eccentricities. Here, we report on first unambiguous identification a LMWD in an eccentric (e=0.13) orbit with millisecond pulsar, which directly contradicts this picture. We use our spectra and radio-timing...
Abstract We report the timing results for PSR J2234+0611, a 3.6 ms pulsar in 32 day, eccentric ( e = 0.13) orbit with helium white dwarf. The precise and nature of allow measurements an unusual number parameters: (a) proper motion 27.10(3) mas yr −1 parallax 1.05(4) resulting distance 0.95(4) kpc; enabling estimate transverse velocity, 123(5) km s . Together previously published spectroscopic systemic radial this allows 3D determination system’s velocity; (b) rate advance periastron yields...
We present timing solutions for ten pulsars discovered in 350 MHz searches with the Green Bank Telescope. Nine of these were Northern Celestial Cap survey and one was by students Pulsar Search Collaboratory program analysis drift-scan data. Following discovery confirmation Telescope, has yielded phase-connected high precision measurements rotational astrometric parameters. Eight are slow isolated, including PSR J0930$-$2301, a pulsar nulling fraction lower limit $\sim$30\% timescale seconds...
Four major problems that complicate read and write accesses to instances in object-oriented databases are discussed. The four are: difficulty providing ad hoc commutativity relations, lacking overhead, escalation, pseudo-conflicts. It is shown all of these can be solved by a simple form commutativity. This kind syntactically extracted from the source codes methods at compile-time. Then, an efficient linear algorithm calculates transitive access vectors. Finally, vectors translated into...
Abstract We present the discovery and timing solutions of four millisecond pulsars (MSPs) discovered in Arecibo 327 MHz Drift-Scan Pulsar Survey. Three these are binary systems, consisting a redback (PSR J2055+1545), black widow J1630+3550), neutron star–white dwarf J2116+1345). The fourth MSP, PSR J2212+2450, is isolated. multiyear as well polarization properties across range radio frequencies for each pulsar. perform multiwavelength search emission from systems find an optical counterpart...
We present the discovery and timing solutions of four millisecond pulsars (MSPs) discovered in Arecibo 327 MHz Drift-Scan Pulsar Survey. Three these are binary systems, consisting a redback (PSR J2055+1545), black widow J1630+3550), neutron star-white dwarf J2116+1345). The fourth MSP, PSR J2212+2450, is isolated. multiyear as well polarization properties across range radio frequencies for each pulsar. perform multiwavelength search emission from systems find an optical counterpart...
We present some formal properties of (symmetrical) commutativity, the major criterion used in transactional systems, which allow us to fully understand its advantages and disadvantages. The main result is that commutativity subject same limitation as compatibility for arbitrary objects. However, has also a number attracting properties, one related recovery and, our knowledge, not been exploited literature. Advantages disadvantages are illustrated on abstract data types interest. show how...
Abstract Recycled pulsars are old (≳10 8 yr) neutron stars that descendants from close, interacting stellar systems. In order to understand their evolution and population, we must find study the largest possible number of recycled in a way is as unbiased possible. this work, present discovery timing solutions five binary systems (PSRs J0509+0856, J0709+0458, J0732+2314, J0824+0028, J2204+2700) one isolated millisecond pulsar (PSR J0154+1833). These were found data Arecibo 327 MHz Drift-Scan...
Abstract We present timing solutions for four pulsars discovered in the Green Bank Northern Celestial Cap survey. All are isolated with spin periods between 0.26 and 1.84 s. PSR J0038−2501 has a s period derivative of 7.6 × 10 −19 −1 , which is unusually low similar periods. This may be simply an extreme value pulsar or it could indicate unusual evolution path J0038−2501, such as disrupted recycled from binary system orphaned central compact object (CCO). Correcting observed spin-down rate...