Status of the LISA Enhanced Temperature Subsystem (LETS) @LISAcommunity

Uploaded August 2020 | Updated September 2026, 59 minutes ago

Status of the LISA Enhanced Temperature Subsystem (LETS)

M. Nofrarias, K. Abich, M. Gohlke, V. Gualani, D. Roma, J. Ramos, J. Sanjuan

Temperature dependent effects are typically dominant in the low frequency regime, which is the main scientific band for space-borne gravitational detectors. In LISA, temperature fluctuations in the sub-millihertz will be ubiquitous to the satellite with a potential to impact key subsystems in the measurement chain, from thermal induced forces applied directly to the test mass to temperature induced path-length variations in interferometers.

LETS (LISA Enhanced Temperature Subsystem) is an ESA funded project which aims to design and test a prototype temperature subsystem reaching a 1uK/√Hz down to 1mHz and relaxing as 1/f^2 towards 0.1 mHz, which represents a one order of magnitude improvement with respect the temperature subsystem flown in LISA Pathfinder. The activities in LETS include the design and test of a new front-end electronics and a test bench, which must isolate the sensors from the environmental temperature fluctuations and hence guarantee the required temperature stability inside. Both the design of the front-end electronics and the test bench are particularly challenging activities for an experiment working in the sub-millihertz regime.

In this contribution we will describe the current status of LETS and the next steps towards their implementation as the LISA temperature subsystem.

Prospects for Detecting Exoplanets around Double White Dwarfs with LISA and Taiji

LISA Symposium XIV Parallel A Beyond LISA Part 2

$Numerical Relativity Surrogate model for eccentric binary black hole gravitational waveform Numerical Relativity Surrogate model for eccentric binary black hole gravitational waveform Tousif Islam, Vijay Varma, Jacqueline Lodman, Scott Field and Gaurav Khanna Though Numerical Relativity (NR) simulations provide the most accurate gravitational waveforms for binary black holes (BBHs), they are computationally expensive, taking days to weeks to generate one single waveform. NR surrogate waveform models are computationally cheaper without sacrificing accuracy. While surrogate models for non-spinning, aligned spin and precessing BBHs are quite reliable, efforts to build an eccentric NR surrogate model are still at an early stage. We provide detailed data decomposition and parameterization strategies to build an effective NR surrogate for eccentric BBHs waveforms. Based on the proposed framework, we then present a time domain, inspiral-merger-ringdown NR surrogate model for eccentric binary black holes for mass ratio $q=1$. We call it NRSur2dq1Ecc. The model includes the (l=2,m=2), (l=3,m=2) and (l=4,m=4) spin-weighted spherical harmonic modes. The odd $m$ modes are zero due to the symmetry of the system. We parameterize the effect of eccentricity via eccentric parameter $e_w$ and mean anomaly $l_w$. This model has been trained against 41 NR waveforms with mass ratio $q=1$, $e_wlt0.175$ and $0ltl_wlt2pi$ (as estimated at a reference time of $t_{ref} 4200M$); and uses Gaussian Process Regression to build the fits across parameter space. We show that our model can accurately predict NR waveforms with mismatches $approx 10^{-3}$ and can recover subtle effects like mode-mixing in the ringdown signal. The method proposed here would pave the way forward for constructing any future surrogate waveform model with eccentric binaries.$

IfoCAD simulations for TTL noise analyses in LISA

LISA Symposium XIV Parallel A LISA Instrumentation 3 Part 2

Experimental backscatter measurement rig for LISA beam dumps and FIOS characterisation

About the modes and tones of Black Hole Ringdowns

LISA Symposium XIV Day 1 Plenary Block 1 Complete

Predictions for Ultra Compact X-Ray Binaries from Combined GW and Electromagnetic Wave Observations