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The 101-110th REM talks

The 110th REM: December 22th, 2022, Thursday

• Time: 11:00-12:00
• Speaker: Ryudo Tsukizaki (ISAS)

  • Title: "Introduction to Space Propulsion"

    • Abstract:

      In this seminar, a wide variety of space propulsion, such as, cold gas thrusts, chemical thrusters, and solar/nuclear electric thrusters will be introduced. The speaker expects discussion with audience on the possibility of the application of his speciality, low-power electric thrusters, such as 30-W gridded ion thrusters and 1-W electrospray thrusters to the gravitational wave detection in space.

The 109th REM: December 13th, 2022, Tuersday

• Time: 11:00-12:00
• Speaker: Yu Takahashi (NASA Jet Propulsion Laboratory (JPL))

  • Title: "Navigation around Jovian environment and small bodies"

    • Abstract:

      Juno entered its extended mission last year after five years of prime mission in the Jovian environment. The Ganymede flyby in July 2021 kicked off the sequence of flybys that lower Juno’s orbital period,
       allowing for close range observation of Europa in September 2022 and Io in December 2023. We will discuss the design principles of the Juno reference trajectory and the navigation results from the Ganymede and Europa flybys. The second part of the talk will
       discuss navigation in the small body environment, focusing on the OSIRIS-REx mission. The OSIRIS-REx spacecraft observed particles sporadically ejecting from Bennu’s surface, which could have caused catastrophic damage to the spacecraft and complicated mission
       operations. However, the same particles turned out to be very fortuitous “instruments” that allowed the radio science team to estimate the gravity field at precision that would otherwise be unachievable. We will discuss our methods to estimate these particles’
       trajectories and how they relate to the gravity field and surface environment around Bennu.

The 108th REM: October 27th, 2022, Thursday

• Time: 11:00-12:00
• Speaker: Satoshi Tanioka (Syracuse University)

  • Title: "Current status of AlGaAs coatings"

    • Link to the material

    • Abstract:

      Thermal noise in high-reflectivity mirror coatings is a limiting factor in ground-based gravitational wave detectors. Reducing this coating thermal noise improves the sensitivity of detectors and enriches the scientific outcome of observing runs. Crystalline gallium arsenide and aluminum-alloyed gallium arsenide (referred to as AlGaAs) coatings are promising coating candidates for future upgrades of gravitational wave detectors because of their low coating thermal noise. In this talk, recent progress in AlGaAs coating research will be presented.

The 107th REM: August 19th, 2022, Friday

• Time: 11:00-12:00
• Speaker: Leo Tsukada (Penn State University)

  • Title: "Low-latency detection of the gravitational waves from compact binary coalescences"

    • Abstract:

      Since the first detection of the gravitational wave from a binary black hole, the LIGO-Virgo-KAGRA (LVK) collaboration has detected in total 90 events from compact binary coalescences, establishing the field of gravitational wave astronomy. In addition to shedding light on the properties of compact objects e.g. black holes and neutron stars, the joint observation of such objects together with electromagnetic emission will bring us further enriched insight on nuclear physics and cosmology. Early 2023, the fourth observing run is going to take place and various methods have been extensively developed towards it. Today, I will talk about methods to detect gravitational waves in low latency, which plays a crucial role in so-called multi-messenger astronomy. In particular, this talk will be focused on the methodology of a low-latency detection pipeline, GstLAL. GstLAL can also incorporate the detection method with negative latency, i.e. early warning. I will briefly describe its prospect in the upcoming forth observing run by the LVK collaboration.

The 106th REM: July 28th, 2022, Thursday

• Time: 11:00-12:00
• Speaker: Masayuki Nakano (LIGO, LLO)

  • Title: "The status of LLO commissioning for O4"

    • Link to the material

The 105th REM: June 16th, 2022, Thursday

• Time: 11:00-12:00
• Speaker: Ryosuke Sugimoto (SOKENDAI/JAXA)

  • Title: "Demonstration of back-linked Fabry-Perot interferometer towards space gravitational wave antenna"

    • Link to the material

The 104th REM: May 19th, 2022, Thursday

• Time: 11:00-12:00
• Speaker: Shoichi Oshino (ICRR)

  • Title: "Current status of KAGRA for O4 observation"

    • Link to the material

    • Abstract:

      KAGRA is currently undergoing upgrade work in preparation for the fourth phase of international joint observations with LIGO and Virgo scheduled to begin in December 2022. KAGRA has two features: built underground and the mirrors are cooled to low temperatures. These are features that predate the third-generation gravitational wave telescopes that will be built in the future. This presentation will introduce the gravitational wave telescope KAGRA, focusing on upgrading works being done.

The 102nd REM: November 15th, 2019, Friday

• Time: 13:00-14:00
• Location: ICRR, the Kashiwanoha campus (tentative)
• Speaker: Kyohei Kawaguchi (ICRR, University of Tokyo)

  • Title: "Modeling gravitational waveforms and electromagnetic signals from neutron star binary mergers"

  • Link to the material

• Zoom connection information

  • Meeting URL: https://zoom.us/j/5045179604

  • password: ask the organizers

The 101st REM / ISAS Astrophysics Colloquium : August 9th, 2019, Friday

• Time: 13:00-14:00
• Location: Room 1537, Bild.A, 5F in JAXA Sagamihara campus
• Speaker: Morio Toyoshima (NICT)

  • Title: "Recent Trends of Space Laser Communications"

  • a link to the material (password protected)

• Information for Zoom remote connection

  • Meeting URL: https://zoom.us/j/5045179604

  • password: ask an organizer

• Jointly organized with the ISAS Astrophysics Colloquia