first_img Categories: Good Morning San Diego, Local San Diego News Tags: Decision 2018 FacebookTwitter Lauren Phinney Lauren Phinney, Updated: 2:55 PM 00:00 00:00 spaceplay / pause qunload | stop ffullscreenshift + ←→slower / faster ↑↓volume mmute ←→seek  . seek to previous 12… 6 seek to 10%, 20% … 60% XColor SettingsAaAaAaAaTextBackgroundOpacity SettingsTextOpaqueSemi-TransparentBackgroundSemi-TransparentOpaqueTransparentFont SettingsSize||TypeSerif MonospaceSerifSans Serif MonospaceSans SerifCasualCursiveSmallCapsResetSave SettingsDemocrat and former Assemblyman Nathan Fletcher is running for termed-out Supervisor Ron Roberts seat in District 4. Lauren Phinney spoke to Fletcher in studio about his campaign.Fletcher dropped out of politics a few years ago after a couple of angst-filled losses while taking flack for switching political parties. Most recently he was working for Qualcomm and teaching a class at UCSD. The urge to serve returned along with a long-term opportunity to end the GOP’s monopoly at the County level.To learn more about Nathan Fletcher, visit: https://www.nathanfletcher.com/ center_img June 4, 2018 Nathan Fletcher running for District 4 Posted: June 4, 2018last_img read more


first_img Citation: Astronomers detect synchronous X-ray and radio mode switching of the pulsar PSR B0823+26 (2018, August 20) retrieved 18 August 2019 from https://phys.org/news/2018-08-astronomers-synchronous-x-ray-radio-mode.html Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Mode changing and giant pulses found in a millisecond pulsar © 2018 Phys.org More information: Discovery of synchronous X-ray and radio moding of PSR B0823+26, arxiv.org/abs/1808.01901AbstractSimultaneous observations of PSR B0823+26 with ESA’s XMM-Newton, the Giant Metrewave Radio Telescope and international stations of the Low Frequency Array revealed synchronous X-ray/radio switching between a radio-bright (B) mode and a radio-quiet (Q) mode. During the B mode we detected PSR B0823+26 in 0.2−2 keV X-rays and discovered pulsed emission with a broad sinusoidal pulse, lagging the radio main pulse by 0.208 ± 0.012 in phase, with high pulsed fraction of 70−80%. During the Q mode PSR B0823+26 was not detected in X-rays (2 σ upper limit a factor ~9 below the B-mode flux). The total X-ray spectrum, pulse profile and pulsed fraction can globally be reproduced with a magnetized partially ionized hydrogen atmosphere model with three emission components: a primary small hot spot (T∼3.6×106 K, R∼17 m), a larger cooler concentric ring (T∼1.1×106 K, R∼280 m) and an antipodal hot spot (T∼1.1×106 K, R∼100 m), for the angle between the rotation axis and line of sight direction ∼66∘. The latter is in conflict with the radio derived value of (84±0.7)∘. The average X-ray flux within hours-long B-mode intervals varied by a factor ±20%, possibly correlated with variations in the frequency and lengths of short radio nulls or short durations of weak emission. The correlated X-ray/radio moding of PSR B0823+26 is compared with the anti-correlated moding of PSR B0943+10, and the lack of X-ray moding of PSR B1822-09. We speculate that the X-ray/radio switches of PSR B0823+26 are due to variations in the rate of accretion of material from the interstellar medium through which it is passing. An international team of astronomers has detected synchronous X-ray and radio mode switching between radio-bright and a radio-quiet modes in the pulsar PSR B0823+26. The discovery marks the second time that such synchronous mode switching has been observed in a pulsar. The finding is detailed in a paper published August 6 on arXiv.org. GMRT observation at 325 MHz of PSR B0823+26 on 2017 April 20, showing as a typical example PSR B0823+26 in B mode during 2500 single-pulse sequences, or ∼ 22 minutes of the total duration of ∼ 7.5 hours in B mode. Observation time versus pulsar phase centred on the main pulse with underneath the integrated profile of the main pulse, and to the left the average energy per pulse in arbitrary units. Credit: Hermsen et al., 2018. To date, synchronous X-ray and radio mode switching has been identified only in one old and nearly aligned pulsar known as PSR B0943+10. Therefore, astronomers are interested in finding such behavior in other objects in order to improve knowledge about the poorly understood mechanisms behind this activity.The new study, conducted by a group of scientists led by Willem Hermsen of the University of Amsterdam in the Netherlands, presents another example of a pulsar experiencing synchronous X-ray and radio mode switching. The discovery was made as a result of observations with ESA’s XMM-Newton spacecraft, the Giant Metrewave Radio Telescope (GMRT) in India and international stations of the Low-Frequency Array (LOFAR).”We observed the radio-mode switching PSR B0823+26 for about 39 hours simultaneously in X-rays and the radio band and report the discovery of synchronous correlated X-ray and radio mode switching,” the researchers wrote in the paper.PSR B0823+26, located some 1,000 light years away from the Earth, is one of the brightest radio pulsars in the Northern sky. It has a period about 530 milliseconds, a spin-down age of approximately 4.9 million years and an inferred magnetic field of around 980 billion G.The observations performed by Hermsen’s team allowed the researchers to find that PSR B0823+26 switches between a radio-bright (B) mode and a radio-quiet (Q) mode. In particular, the pulsar was found to be in the radio B mode during five out of six XMM-Newton observations and in the Q mode during only one observation. Moreover, the pulsar spent only approximately 15 percent of the time in Q mode over entire radio observational campaign with GMRT and LOFAR.Notably, during the Q mode, the researchers did not detect PSR B0823+26 in X-rays with an upper limit almost an order of magnitude lower than the reported flux in the B mode. They emphasized that this is a surprising result, as PSR B0943+10 is known to showcase anti-correlated mode switches.The authors of the paper also try to explain the nature of the observed synchronous X-ray and radio mode switching in PSR B0823+26. They assume that at the moment, the most plausible hypothesis is that this behavior is due to variations in the rate of accretion of material from the interstellar medium through which it is passing.”We are speculating that in PSR B0823+26, we are not seeing ‘true’ mode-changing but the sudden appearance of strong bursts whose intensities follow a self-similar (i.e. fractal) distribution over a wide range of timescales. Such a system could be identified as exhibiting self-organized criticality. In this context, we speculate that PSR B0823+26 is accreting material from a debris disk or the interstellar medium through which it is passing, to explain some of its X-ray characteristics,” the astronomers concluded.last_img read more


first_imgSimilar plants have also come up at Delhi Metro Rail Corporation’s residential colonies at Shastri Park, Sarita Vihar and Yamuna Bank where about 260 kilolitres of water is being reused, primarily in watering gardens and toilets.The five depots where the facilities have been installed are – Sarita Vihar, Shastri Park, Yamuna Bank, Sultanpur and Khyber Pass.The plants at Najafgarh and Dwarka are under renovation.Officials said plans are afoot to have similar facilities in the depots which are going to come up as part Phase-III of expansion and “feasibility studies” are being conducted to explore the possibility of installing similar plants at other locations.As part of its water conservation efforts, DMRC also has 470 rain water harvesting pits at 99 locations with a total capacity of 7,844 cubic metres, a statement said. It is also developing an “Environmental Management System” to promote awareness on the need to conserve water among employees and stakeholders.last_img read more


first_imgInfants and new born kids, if seated in cars for more than 30 minutes, may be at a risk of suffocation, suggests a study published in the Daily Mail.According to the study, very young babies whose neck muscles are not strong enough to stop their heads flopping forward could stop breathing. This increases the risk they will be unable to breathe — with potentially fatal results.“There should be separate advice for very young babies. If you can avoid a journey, it’s probably better to do so, restricted to no more than half an hour or so. But try to avoid unnecessary car journeys with young babies,” said Peter Fleming, Pediatrician at the Bristol University. Also Read – Add new books to your shelfResearch carried out by the researchers used a laboratory in a laboratory to replicate the effects of sleeping in a car seat during a car journey at 30mph.After half an hour in the seat, the amounts of oxygen in the blood of babies under two months old were found to have dropped ‘significantly’ while their heart rates increased.The authors said their findings still mean babies should travel in a properly secured child seat during car journeys — as is required by law. But they advise that an adult should sit next to the baby to make sure the infant is breathing properly.“There have been reports of deaths of infants who have been left in a sitting position, including in car seats both on journeys, and when parents have used it as an alternative to a push chair or cot for the infant to sleep in,” he added.last_img read more