Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize ...Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.展开更多
We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be class...We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.展开更多
To determine the characteristics and potential indicators of modern typhoon deposition in a sandy lagoon off the coast of Guangdong Province(southern China),we analysed the ^(210)Pb,sedimentology,and microfossils of s...To determine the characteristics and potential indicators of modern typhoon deposition in a sandy lagoon off the coast of Guangdong Province(southern China),we analysed the ^(210)Pb,sedimentology,and microfossils of samples from ten cores obtained before and after the passage of Typhoon Rammasun in 2014.Typhoon deposition showed a thinning trend from internal areas of the lagoon to its mouth,with the maximum thickness inside the lagoon of~35 cm.These typhoon deposits are dominated by overwash and differ from sediments deposited under normal weather conditions.Under normal weather conditions,lagoon sediment has a210 Pb curve that follows a model of exponential decay,has a unimodal granularity frequency curve,and lacks organic matter and microfossils(diatoms and foraminifera).However,210 Pb is low in the typhoon deposits,the grain size is coarse,and the granularity frequency curve is obviously bimodal.There are also abundant foraminifera in the typhoon deposits.We found a clear double-layered structure in the typhoon deposits,which was caused by strong hydrodynamic disturbance that mixed sediments originally from the offshore area with those of the lagoon.The lower layer has coarse-grained particles with medium sorting,low organic matter content,and low diatom content.The upper layer has fine-grained particles with poor sorting,high organic matter content,and abundant diatoms.The rate of fragmentation of diatoms in the upper layer was very high(40%-60%).The diatom assemblage contained offshore and freshwater species carried by storm runoff.Therefore,we believe that the sediments of this typical sand bar-lagoon environment retain evidence of typhoon events along the southern China coast that is displayed in the marked sedimentological and microfossil characteristics.展开更多
Purpose The Hard X-ray Modulation Telescope is China’s first X-ray astronomy satellite launched on June 15,2017,dubbed Insight-HXMT.Active and passive thermal control measures are employed to keep devices at suitable...Purpose The Hard X-ray Modulation Telescope is China’s first X-ray astronomy satellite launched on June 15,2017,dubbed Insight-HXMT.Active and passive thermal control measures are employed to keep devices at suitable temperatures.In this paper,we analyzed the on-orbit thermal monitoring data of the first 5 years and investigated the effect of thermal deformation on the point spread function(PSF)of the telescopes.Methods We examined the data of the on-orbit temperatures measured using 157 thermistors placed on the collimators,detectors and their support structures and compared the results with the thermal control requirements.The thermal deformation was evaluated by the relative orientation of the two star sensors installed on the main support structure.Its effect was estimated with evolution of the PSF obtained with calibration scanning observations of the Crab nebula.Conclusion The on-orbit temperatures met the thermal control requirements thus far,and the effect of thermal deformation on the PSF was negligible after the on-orbit pointing calibration.展开更多
基金supported by the National Key Research and Development Program of China(grants Nos.2022YFC2205000 and 2021YFC2203400)。
文摘Searching for primordial gravitational waves in the cosmic microwave background(CMB)polarization signal is one of the key topics in modern cosmology.Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed.Using a modular design,the telescope focal plane is simplified to several detector modules.Each module has hundreds of pixels including antenna arrays,detector arrays,and readout arrays.The antenna arrays,as the beam defining component,determine the overall optical response of the detector module.In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module.The arrays are fabricated from 426 inch silicon wafers including 456 antennas,7%more pixels than the usual design.The overall in-band cross polarization is smaller than-20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.
基金the HXMT mission,a project funded by China National Space Administration(CNSA)and the Chinese Academy of Sciences(CAS)supported by the National Key R&D Program of China(2016YFA0400800)the National Natural Science Foundation of China(Grant Nos.11673023,U1838201,U1838115,U1838111,U1838202,11733009 and U1838108)。
文摘We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.
基金the Key Program of National Natural Science Foundation of China(Grant No.41930538)the National Science Foundation of China(Grant No.41306083)+1 种基金the National Key Research and Development Program of China(Grant No.2019YFE0124700)the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources of China(Grant Nos.2019018,2019026,and 2020017)。
文摘To determine the characteristics and potential indicators of modern typhoon deposition in a sandy lagoon off the coast of Guangdong Province(southern China),we analysed the ^(210)Pb,sedimentology,and microfossils of samples from ten cores obtained before and after the passage of Typhoon Rammasun in 2014.Typhoon deposition showed a thinning trend from internal areas of the lagoon to its mouth,with the maximum thickness inside the lagoon of~35 cm.These typhoon deposits are dominated by overwash and differ from sediments deposited under normal weather conditions.Under normal weather conditions,lagoon sediment has a210 Pb curve that follows a model of exponential decay,has a unimodal granularity frequency curve,and lacks organic matter and microfossils(diatoms and foraminifera).However,210 Pb is low in the typhoon deposits,the grain size is coarse,and the granularity frequency curve is obviously bimodal.There are also abundant foraminifera in the typhoon deposits.We found a clear double-layered structure in the typhoon deposits,which was caused by strong hydrodynamic disturbance that mixed sediments originally from the offshore area with those of the lagoon.The lower layer has coarse-grained particles with medium sorting,low organic matter content,and low diatom content.The upper layer has fine-grained particles with poor sorting,high organic matter content,and abundant diatoms.The rate of fragmentation of diatoms in the upper layer was very high(40%-60%).The diatom assemblage contained offshore and freshwater species carried by storm runoff.Therefore,we believe that the sediments of this typical sand bar-lagoon environment retain evidence of typhoon events along the southern China coast that is displayed in the marked sedimentological and microfossil characteristics.
基金This work was based on the data from Insight-HXMT mission,a project funded by the China National Space Administration(CNSA)and the Chinese Academy of Sciences(CAS)We gratefully acknowledge the support from the National Program on Key Research and Development Project(Grant No.2021YFA0718500)from the Ministry of Science and Technology of China(MOST)+2 种基金All authors appreciate the supports from the National Natural Science Foundation of China under Grants 12273043,U1838201,U1838202,U1938102,and U1938108This work was partially supported by International Partnership Program of Chinese Academy of Sciences(Grant No.113111KYSB20190020)Appreciate Zeyu Song from IHEP for meticulous translation and revision.Appreciate Yongping Li from IHEP for helping with star sensor quaternion calculation.
文摘Purpose The Hard X-ray Modulation Telescope is China’s first X-ray astronomy satellite launched on June 15,2017,dubbed Insight-HXMT.Active and passive thermal control measures are employed to keep devices at suitable temperatures.In this paper,we analyzed the on-orbit thermal monitoring data of the first 5 years and investigated the effect of thermal deformation on the point spread function(PSF)of the telescopes.Methods We examined the data of the on-orbit temperatures measured using 157 thermistors placed on the collimators,detectors and their support structures and compared the results with the thermal control requirements.The thermal deformation was evaluated by the relative orientation of the two star sensors installed on the main support structure.Its effect was estimated with evolution of the PSF obtained with calibration scanning observations of the Crab nebula.Conclusion The on-orbit temperatures met the thermal control requirements thus far,and the effect of thermal deformation on the PSF was negligible after the on-orbit pointing calibration.
