Alexander Harvey Nitz
@alexnitz.com
Associate Professor of Physics at Syracuse Univ. | Gravitational-wave Astronomer | BlackHoles | NeutronStars | PyCBC developer.
Pinned
Alexander Harvey Nitz
@alexnitz.com
· Sep 17
Gravitational Wave Timeline of Observations
YouTube video by Syracuse Gravity
www.youtube.com
In honor of the 10th anniversary of observing gravitational waves, I assembled this little video showing the observations over time. Come give a listen to the sound of the Universe!
www.youtube.com/watch?v=z7t8...
www.youtube.com/watch?v=z7t8...
Reposted by Alexander Harvey Nitz
Looking for multiband gravitational-wave sources in #LISA data - a needle in a haystack problem!
Shichao Wu presented a search for stellar origin binary black hole signals in LISA & next generation ground-based detectors (LISA+3G) with pyCBC.
#GR26Amaldi16
Find out more: arxiv.org/abs/2506.01898
Shichao Wu presented a search for stellar origin binary black hole signals in LISA & next generation ground-based detectors (LISA+3G) with pyCBC.
#GR26Amaldi16
Find out more: arxiv.org/abs/2506.01898
July 14, 2025 at 11:08 PM
Looking for multiband gravitational-wave sources in #LISA data - a needle in a haystack problem!
Shichao Wu presented a search for stellar origin binary black hole signals in LISA & next generation ground-based detectors (LISA+3G) with pyCBC.
#GR26Amaldi16
Find out more: arxiv.org/abs/2506.01898
Shichao Wu presented a search for stellar origin binary black hole signals in LISA & next generation ground-based detectors (LISA+3G) with pyCBC.
#GR26Amaldi16
Find out more: arxiv.org/abs/2506.01898
In honor of the 10th anniversary of observing gravitational waves, I assembled this little video showing the observations over time. Come give a listen to the sound of the Universe!
www.youtube.com/watch?v=z7t8...
www.youtube.com/watch?v=z7t8...
Gravitational Wave Timeline of Observations
YouTube video by Syracuse Gravity
www.youtube.com
September 17, 2025 at 7:49 PM
In honor of the 10th anniversary of observing gravitational waves, I assembled this little video showing the observations over time. Come give a listen to the sound of the Universe!
www.youtube.com/watch?v=z7t8...
www.youtube.com/watch?v=z7t8...
One can infer a bit about the masses of the black hole and neutron star already. The chirp mass would be something near ~ 1.96 solar masses. That's a particular combination of the two object masses, so if the NS were 1.4 solar masses that would mean the black hole is ~ 3.8 solar masses.
February 6, 2025 at 10:41 PM
One can infer a bit about the masses of the black hole and neutron star already. The chirp mass would be something near ~ 1.96 solar masses. That's a particular combination of the two object masses, so if the NS were 1.4 solar masses that would mean the black hole is ~ 3.8 solar masses.
The localization of this event is somewhat large and it is over a billion light years away. However, the mass of this merger might allow for the neutron star to be torn apart and produce detectable light.
February 6, 2025 at 10:34 PM
The localization of this event is somewhat large and it is over a billion light years away. However, the mass of this merger might allow for the neutron star to be torn apart and produce detectable light.
Fun gravitational-wave news!
An neutron star - black hole merger was potentially just observed! ⚫⚪ The false alarm rate is ~ 1 per 25 years, so this will need further investigation. With luck, there may be electromagnetic emission from the collision.
gracedb.ligo.org/superevents/...
An neutron star - black hole merger was potentially just observed! ⚫⚪ The false alarm rate is ~ 1 per 25 years, so this will need further investigation. With luck, there may be electromagnetic emission from the collision.
gracedb.ligo.org/superevents/...
GraceDB | S250206dm
gracedb.ligo.org
February 6, 2025 at 10:34 PM
Fun gravitational-wave news!
An neutron star - black hole merger was potentially just observed! ⚫⚪ The false alarm rate is ~ 1 per 25 years, so this will need further investigation. With luck, there may be electromagnetic emission from the collision.
gracedb.ligo.org/superevents/...
An neutron star - black hole merger was potentially just observed! ⚫⚪ The false alarm rate is ~ 1 per 25 years, so this will need further investigation. With luck, there may be electromagnetic emission from the collision.
gracedb.ligo.org/superevents/...
Interested in a postdoctoral position helping to design the next-generation of US gravitational-wave observatories? There is still time to apply! Please consider doing so or share with someone who may be interested.
www.sujobopps.com/postings/107...
www.sujobopps.com/postings/107...
January 5, 2025 at 1:51 AM
Interested in a postdoctoral position helping to design the next-generation of US gravitational-wave observatories? There is still time to apply! Please consider doing so or share with someone who may be interested.
www.sujobopps.com/postings/107...
www.sujobopps.com/postings/107...
Yes, absolutely! He's retired now, but he was the senior faculty of the group at Syracuse when I was a PhD student.
December 11, 2024 at 3:14 AM
Yes, absolutely! He's retired now, but he was the senior faculty of the group at Syracuse when I was a PhD student.
We are hiring! Work on the design of the Open Control and Analysis Architecture for Cosmic Explorer, the U.S. next-generation gravitational-wave observatory. Candidates will be considered at the postdoctoral level or as research assistant professor with suitable experience.
tinyurl.com/5n8t6n7y
tinyurl.com/5n8t6n7y
Postdoctoral Scholar - Gravitational Wave Detector Design
The Physics Department at Syracuse University invites applications for a postdoctoral position to work on the design of the Open Control and Analysis Architecture for Cosmic Explorer, the planned U.S....
tinyurl.com
December 2, 2024 at 4:00 PM
We are hiring! Work on the design of the Open Control and Analysis Architecture for Cosmic Explorer, the U.S. next-generation gravitational-wave observatory. Candidates will be considered at the postdoctoral level or as research assistant professor with suitable experience.
tinyurl.com/5n8t6n7y
tinyurl.com/5n8t6n7y
So CE/ET, LISA, and PTAs will be sensitive to different types of sources (or in different parts of their evolution), but CE/ET will be an order of magnitude (or more) more sensitive than current LIGO/Virgo.
November 12, 2024 at 10:33 PM
So CE/ET, LISA, and PTAs will be sensitive to different types of sources (or in different parts of their evolution), but CE/ET will be an order of magnitude (or more) more sensitive than current LIGO/Virgo.
How does this related to say LISA or pulsar timing? Both of these use arm lengths much longer than ground-based observatories. However, their ability to measure displacements is actually *much* worse. LISA's design will be sensitive to 10^-4 -> 10^-1 H, while Pulsar timing focusing on ~ 10^-8 Hz.
November 12, 2024 at 10:33 PM
How does this related to say LISA or pulsar timing? Both of these use arm lengths much longer than ground-based observatories. However, their ability to measure displacements is actually *much* worse. LISA's design will be sensitive to 10^-4 -> 10^-1 H, while Pulsar timing focusing on ~ 10^-8 Hz.
In many ways a CE facility is endgame for gravitational-wave astronomy on the ground. There is the potential for upgrading the detectors within the facilities, but there would likely not be an effort for an even larger observatory on the ground.
November 12, 2024 at 10:33 PM
In many ways a CE facility is endgame for gravitational-wave astronomy on the ground. There is the potential for upgrading the detectors within the facilities, but there would likely not be an effort for an even larger observatory on the ground.
You can't build much longer than 40km (say 400 km) on the earth due to civil engineering problems (we need actually arms not following earth curvature) and issues with designing and controlling a cavity. The returns would not be as high as you'd hope even if you could solve the engineering issues.
November 12, 2024 at 10:33 PM
You can't build much longer than 40km (say 400 km) on the earth due to civil engineering problems (we need actually arms not following earth curvature) and issues with designing and controlling a cavity. The returns would not be as high as you'd hope even if you could solve the engineering issues.
Ground based detectors because they are fixed in place, use resonant cavities for their arms to store the laser light. This increases the "effective" arm length by orders of magnitude (or conversely allows them to measure very small displacements because they average the measurement of many photons)
November 12, 2024 at 10:33 PM
Ground based detectors because they are fixed in place, use resonant cavities for their arms to store the laser light. This increases the "effective" arm length by orders of magnitude (or conversely allows them to measure very small displacements because they average the measurement of many photons)
If you could ignore all other considerations, longer arms are better because the gravitational wave causes a larger displacement, however, in practice you can't ignore how you actually measure this displacement itself.
November 12, 2024 at 10:33 PM
If you could ignore all other considerations, longer arms are better because the gravitational wave causes a larger displacement, however, in practice you can't ignore how you actually measure this displacement itself.
Great question with a lot to unpack. The short answer is that what matters is the combination of measurement method/technology + arm length. CE is the sweet spot for what you can build on the Earth and will have strictly better sensitivity than current ground based detectors at all frequencies.
November 12, 2024 at 10:33 PM
Great question with a lot to unpack. The short answer is that what matters is the combination of measurement method/technology + arm length. CE is the sweet spot for what you can build on the Earth and will have strictly better sensitivity than current ground based detectors at all frequencies.
Interested in the future of gravitational-wave astronomy?
Cosmic Explorer, the proposed US 40 km gravitational-wave observatories will observe millions of compact-binary mergers throughout the Universe and cosmic time.
CE will hopefully be joined by the Einstein Telescope and space-based LISA.
Cosmic Explorer, the proposed US 40 km gravitational-wave observatories will observe millions of compact-binary mergers throughout the Universe and cosmic time.
CE will hopefully be joined by the Einstein Telescope and space-based LISA.
November 11, 2024 at 5:56 PM
Interested in the future of gravitational-wave astronomy?
Cosmic Explorer, the proposed US 40 km gravitational-wave observatories will observe millions of compact-binary mergers throughout the Universe and cosmic time.
CE will hopefully be joined by the Einstein Telescope and space-based LISA.
Cosmic Explorer, the proposed US 40 km gravitational-wave observatories will observe millions of compact-binary mergers throughout the Universe and cosmic time.
CE will hopefully be joined by the Einstein Telescope and space-based LISA.
I guess all the scientists are moving over here? I don't really talk about much besides science.
Look out for updates on gravitational waves from me and my fantastic students. We study neutron stars and black holes with LIGO and are building tools for Cosmic Explorer and LISA.
Look out for updates on gravitational waves from me and my fantastic students. We study neutron stars and black holes with LIGO and are building tools for Cosmic Explorer and LISA.
November 11, 2024 at 4:39 AM
I guess all the scientists are moving over here? I don't really talk about much besides science.
Look out for updates on gravitational waves from me and my fantastic students. We study neutron stars and black holes with LIGO and are building tools for Cosmic Explorer and LISA.
Look out for updates on gravitational waves from me and my fantastic students. We study neutron stars and black holes with LIGO and are building tools for Cosmic Explorer and LISA.
What if there are highly spinning solar-mass scale binaries?
We report a search for gravitational waves from these unusual binaries, which might include unusual neutron stars, quark stars, hierarchical merger of primordial black holes, or other exotic scenarios.
arxiv.org/abs/2308.16173
We report a search for gravitational waves from these unusual binaries, which might include unusual neutron stars, quark stars, hierarchical merger of primordial black holes, or other exotic scenarios.
arxiv.org/abs/2308.16173
First Targeted Search for Gravitational Waves from Highly Spinning...
Searches for gravitational waves from compact-binary mergers, which to date
have reported nearly 100 observations, have previously ignored binaries whose
components are both light ($< 2 M_\odot$)...
arxiv.org
August 31, 2023 at 7:01 PM
What if there are highly spinning solar-mass scale binaries?
We report a search for gravitational waves from these unusual binaries, which might include unusual neutron stars, quark stars, hierarchical merger of primordial black holes, or other exotic scenarios.
arxiv.org/abs/2308.16173
We report a search for gravitational waves from these unusual binaries, which might include unusual neutron stars, quark stars, hierarchical merger of primordial black holes, or other exotic scenarios.
arxiv.org/abs/2308.16173
Then what do we call the sum of everything else?
August 28, 2023 at 3:39 AM
Then what do we call the sum of everything else?