中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共9条，第1-9条

帮助

条数/页：排序方式：
	A parsec-scale faint jet in the nearby changing-look Seyfert galaxy Mrk 590 期刊论文 OAI收割 Monthly Notices of the Royal Astronomical Society, 2021, 卷号: 502, 期号: 1, 页码: L61-L65 作者: Yang, Jun; van Bemmel, Ilse; Paragi, Zsolt; Komossa, S.; Yuan, Feng \| 收藏 \| 浏览/下载：23/0 \| 提交时间：2022/06/30 galaxies: active galaxies: individual: Mrk 590 galaxies: jets galaxies: Seyfert radio continuum: galaxies active galactic nuclei observational evidence numerical-simulation radio observations accretion flows emission sample quasar evolution core Astronomy & Astrophysics
	Irrigation cooling effect on land surface temperature across China based on satellite observations 期刊论文 OAI收割 SCIENCE OF THE TOTAL ENVIRONMENT, 2020, 卷号: 705, 页码: 10 作者: Yang, Qiquan; Huang, Xin; Tang, Qiuhong \| 收藏 \| 浏览/下载：19/0 \| 提交时间：2020/05/19 Irrigated area Remote sensing Observational evidence Spatiotemporal variation Google Earth Engine
	Irrigation cooling effect on land surface temperature across China based on satellite observations 期刊论文 OAI收割 SCIENCE OF THE TOTAL ENVIRONMENT, 2020, 卷号: 705, 页码: 10 作者: Yang, Qiquan; Huang, Xin; Tang, Qiuhong \| 收藏 \| 浏览/下载：10/0 \| 提交时间：2020/05/19 Irrigated area Remote sensing Observational evidence Spatiotemporal variation Google Earth Engine
	No pulsed radio emission during a bursting phase of a Galactic magnetar 期刊论文 OAI收割 Nature, 2020, 卷号: 587, 页码: 63-65 作者: HXMT \| 收藏 \| 浏览/下载：44/0 \| 提交时间：2022/02/08 Astrophysics - High Energy Astrophysical Phenomena Abstract: Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft íray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft íray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-íray repeater (SGR) bursts were detected in íray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.
	The braking index of PSR B0540-69 and the associated pulsar wind nebula emission after spin-down rate transition 期刊论文 OAI收割 Monthly Notices of the Royal Astronomical Society, 2020, 卷号: 494, 页码: 1865-1870 作者: HXMT \| 收藏 \| 浏览/下载：54/0 \| 提交时间：2022/02/08 stars: magnetic field stars: neutron pulsars: general Astrophysics - High Energy Astrophysical Phenomena Abstract: In 2011 December, PSR B054-69 experienced a spin-down rate transition (SRT), after which the spin-down power of the pulsar increased by $\sim 36{{\ \rm per\ cent}}$. About 1000 d after the SRT, the X-ray luminosity of the associated pulsar wind nebula (PWN) was found to brighten by $32\pm 8{{\ \rm per\ cent}}$. After the SRT, the braking index n of PSR B0540-69 changes from n = 2.12 to 0.03 and then keeps this value for about five years before rising to n = 0.9 in the following years. We find that most of the current models have difficulties in explaining the measured braking index. One exceptive model of the braking index evolution is the increasing dipole magnetic field of PSR B0540-69. We suggest that the field increase may result from some instabilities within the pulsar core that enhance the poloidal component at the price of toroidal component of the magnetic field. The increasing dipole magnetic field will result in the X-ray brightening of the PWN. We fit the PWN X-ray light curve by two models: one assumes a constant magnetic field within the PWN during the brightening and the other assumes an enhanced magnetic field proportional to the energy density of the PWN. It appears that the two models fit the data well, though the later model seems to fit the data a bit better. This provides marginal observational evidence that magnetic field in the PWN is generated by the termination shock. Future high-quality and high-cadence data are required to draw a solid conclusion.
	Constraints on the Sommerfeld-enhanced dark matter annihilation from the gamma rays of subhalos and dwarf galaxies 期刊论文 OAI收割 JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2018, 期号: 4, 页码: 35 作者: Zhang, WH; Lu, BQ; Wu, YL; Zhou, YF \| 收藏 \| 浏览/下载：33/0 \| 提交时间：2018/12/27 MILKY-WAY COSMOLOGICAL SIMULATIONS OBSERVATIONAL EVIDENCE GALACTIC-CENTER MASSES HALO CANDIDATES SIGNATURE SIGNALS LIMITS
	Reasons for the Extremely High-Ranging Planetary Boundary Layer over the Western Tibetan Plateau in Winter 期刊论文 OAI收割 JOURNAL OF THE ATMOSPHERIC SCIENCES, 2016, 卷号: 73, 期号: 5, 页码: 2021-2038 作者: Li, MS (Li, Maoshan); Skerlak, B (Skerlak, Bojan); Rotach, MW (Rotach, Mathias W.); Anel, JA (Anel, Juan A.); Su, Z (Su, Zhonbgo) \| 收藏 \| 浏览/下载：28/0 \| 提交时间：2017/09/30 Numerical Weather Prediction Large-scale Subsidence Asian Summer Monsoon Observational Evidence Residual Layer Land-surface Evolution China Model Height
	Impacts of Cultivated Land Reclamation on the Climate and Grain Production in Northeast China in the Future 30 Years SCI/SSCI论文 OAI收割 2013 Shi Q. L.; Lin Y. Z.; Zhang E. P.; Yan H. M.; Zhan J. Y. 收藏 \| 浏览/下载：27/0 \| 提交时间：2014/12/24 observational evidence envelope models cover projections
	Magnetic reconnection phenomena in interplanetary space 会议论文 OAI收割 World Space Environment Forum (WSEF2002), Adelaide, Australia, 2003 作者: Wei, F. S.; Hu, Q.; Feng, X. S.; Fan, Q. L. 收藏 \| 浏览/下载：29/0 \| 提交时间：2014/04/30 interplanetary magnetic reconnection observational evidence numerical simulation