706 research outputs found
Decade-long timing of four GMRT discovered millisecond pulsars
The discovery and timing follow-up of millisecond pulsars (MSPs) are
necessary not just for their usefulness in Pulsar Timing Arrays (PTAs) but also
for investigating their own intriguing properties. In this work, we provide the
findings of the decade-long timing of the four MSPs discovered by the Giant
Metre-wave Radio Telescope (GMRT), including their timing precision, model
parameters, and newly detected proper motions. We compare the timing results
for these MSPs before and after the GMRT upgrade in 2017, characterise the
improvement in timing precision due to the bandwidth upgrade. We discuss the
suitability of these four GMRT MSPs as well as the usefulness of their
decade-long timing data for the PTA {experiments. It may aid} in the global
effort to improve the signal-to-noise (S/N) of recently detected signature of
gravitational waves in cross-correlation statistics of residuals of MSPs.Comment: Accepted in Astrophysical Journal (APJ) on October 31, 202
A fast radio burst with a low dispersion measure
Fast radio bursts (FRBs) are millisecond pulses of radio emission of
seemingly extragalactic origin. More than 50 FRBs have now been detected, with
only one seen to repeat. Here we present a new FRB discovery, FRB 110214, which
was detected in the high latitude portion of the High Time Resolution Universe
South survey at the Parkes telescope. FRB 110214 has one of the lowest
dispersion measures of any known FRB (DM = 168.90.5 pc cm), and was
detected in two beams of the Parkes multi-beam receiver. A triangulation of the
burst origin on the sky identified three possible regions in the beam pattern
where it may have originated, all in sidelobes of the primary detection beam.
Depending on the true location of the burst the intrinsic fluence is estimated
to fall in the range of 50 -- 2000 Jy ms, making FRB 110214 one of the
highest-fluence FRBs detected with the Parkes telescope. No repeating pulses
were seen in almost 100 hours of follow-up observations with the Parkes
telescope down to a limiting fluence of 0.3 Jy ms for a 2-ms pulse. Similar
low-DM, ultra-bright FRBs may be detected in telescope sidelobes in the future,
making careful modeling of multi-beam instrument beam patterns of utmost
importance for upcoming FRB surveys.Comment: 8 pages, 3 figures, accepted for publication in MNRA
Possible hampered effectiveness of second-line treatment with rituximab-containing chemotherapy without signs of rituximab resistance: a population-based study among patients with chronic lymphocytic leukemia
Rituximab-containing chemotherapy remains a viable frontline treatment option for patients with chronic lymphocytic leukemia (CLL) in the era of novel agents. However, its effectiveness in the second-line setting—in relation to previous rituximab exposure in first-line—has hardly been evaluated in a population-based setting. Therefore, in this comprehensive, population-based study, we assessed the impact of first-line treatment with rituximab-containing chemotherapy on the effectiveness of second-line treatment with rituximab-containing chemot
The effectiveness of ibrutinib in chronic lymphocytic leukaemia: a nationwide, population-based study in the Netherlands
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The Green Bank North Celestial Cap Pulsar Survey. IV: Four New Timing Solutions
We present timing solutions for four pulsars discovered in the Green Bank
Northern Celestial Cap (GBNCC) survey. All four pulsars are isolated with spin
periods between 0.26s and 1.84s. PSR J00382501 has a 0.26s
period and a period derivative of ,
which is unusually low for isolated pulsars with similar periods. This low
period derivative may be simply an extreme value for an isolated pulsar or it
could indicate an unusual evolution path for PSR J00382501, such as a
disrupted recycled pulsar (DRP) from a binary system or an orphaned central
compact object (CCO). Correcting the observed spin-down rate for the Shklovskii
effect suggests that this pulsar may have an unusually low space velocity,
which is consistent with expectations for DRPs. There is no X-ray emission
detected from PSR J00382501 in an archival swift observation, which suggests
that it is not a young orphaned CCO. The high dispersion measure of PSR
J1949+3426 suggests a distance of 12.3kpc. This distance indicates that PSR
J1949+3426 is among the most distant 7% of Galactic field pulsars, and is one
of the most luminous pulsars.Comment: 7 pages, 5 figure
Persistence of Resistant Staphylococcus epidermidis after Single Course of Clarithromycin
Short course of antimicrobial therapy can select resistant bacteria that persist for 4 years or longer
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