John Bolton 

John Bolton was considered one of the most talented and capable radio astronomer/engineers of his era. His enlistment in the Royal Navy circuitiously led to his working with radar during World War 2 and then, after the war, when hearing about Karl Jasnky's work, getting engaged in radio astronomy. Bolton had postulated radio-load stars and began to search for them in the 1940s, well before quasi-stellar objects were discovered.  As it turns out, Bolton discovered the first such object. He was awarded the Gold Medal of the Royal Society and the Bruce Medal. During his career he served as Director of both the Owens Valley Radio Observatory and the Parks radio telescope. Bolton lived to be 71 years old.

Cyril Hazard

Cyril Hazard began his career at Jordell Bank, but ultimately worked on three continents. Although he spent the majority of his career at Cambridge University, he also worked at the Univ. of Sydney, the Univ. of Pittsburgh, and Cornell. In the mid-1980s, he discovered the then highest redshift quasar. Hazard is celebrated for his work that supported and inspired many astronomers and for perfecting a method that allowed many quasars to be located with precision. Hazard lived to be 97 years old.

Allan Sandage

Allan Sandage was the student of the late great Edwin Hubble. He was a prolific scientist across a range of sub-fields in astronomy. He was co-author on the first real paper on galaxy evolution theory (known as "ELS") and spend countless hours working to refine the value of the Hubble-Lemaitre constant. Sandage was a member of the National Academy of Science and a Fellow of the Royal Society. He was honored with an array of awards, including Gold Medal of the Royal Astronomical Scoiety, the National Medal of Science, the Bruce Medal, and the coveted Gruber Prize in Cosmology.  Sandage spent the majority of his career at Carnegie Observatories. He lived to be 84 years old.

Marteen Schmidt 

Marteen Schmidt, in December of 1962, took the spectrum of a star-like object nearest the coordinates sent to him by Cyril Hazard (this first set of coordinates were slightly off), but Schmidt had a hunch he should take the spectrum of the bright "star" first to rule it out.  It was so bright, he saturated the plate. The next night he timed the exposure and saw the telltale signs of  a quasi-stellar object: strange emission lines and a bright blue continuum. By February 1962, Schmidt determined that the emission was the Balmer hydrogen series redshift by 15%. The rest, as they say, is history. In his lifetime, Schmidt was recognized with several honors, including the Gold Medal of the Royal Astronomical Society, the Bruce Medal, and the Kavli Prize. He was a member of the National Academy of Science. Schmidt lived to be 92 years old.

Margaret Burbidge

Margaret Burbidge was a Fellow of the Royal Astronomical Society, (RAS) and was awarded the a RAS Gold Medal, among many other career achievement awards. She was held several leadership posts such as Director of the Royal Greenwich Observatory, and President of  both the American Astronomical Society and the American Association for the Advancement of Science. She helped develop the Faint Object Spectrograph for HST that was used for the now famous HST QSO Absorption Line Key Project. Burbidge finished out her career at UC San Diego, having lived 100 years. 

Geoffrey Burbidge

Geoffrey Burbidge, occasionally and affectionately referred to as the "gadfly of the cosmos," was a formidable presence in the community. His sharp mind was finely tuned into observational details. His great talent was to see, articulate, and challenge percieved  inconsistencies in the interpreations of the data. His direct challenges sharpened the dialog and drove follow-up observations for testing theories and hypotheses. Burbidge was a Fellow of the American Physical Society and was awarded the Warner Prize, the Bruce Medal, the Gold Medal of the Royal Astronomical Scoiety. He worked at Harvard, University of Chicago, Caltech, and Mt Wilson Observatory. In his early career, he would be the "observer of record" on behalf of his wife Margaret, Quasar Pioneer #5, who was a prolific observer. Burbidge lived to be 84 years old.

Roger Lynds 

Roger Lynds  was an insightful observational astronomer and intrument builder who was key to the development of the science of quasar absorption lines. He had a very high aptitude for interpreting the more extreme manifestations of absorption lines in quasar spectra, such as the "forest" blueward of Lyman-alpha emission and extremely broad absorption troughs. He was instrumental in characterizing the flaw in the HST primary mirror shortly after its launch in 1990.  Over his long career, Lynds worked at Berekely, the Dominion Astrophysical Observatory, NRAO (yes, he also did radio astronomy!), and NOAO's Kitt Peak. In addition to his work on absorption lines in quasar spectra, he is famous for discovering gravitaional arcs behind galaxy clusters; he birthed the field of gravitational lenses. Lynds was a member of the National Academy of Sciences, a Miller Fellow (UC Brekeley), a Fellow of the Canada National Research Council, and a Fellow of the American Assocociation for the Advecement of Science. He lived to the age of 94.

John Bahcall

John Bahcall made key early contributions to the interpretation of quasar absorption lines and was the Principle Investigator of  the Hubble Space Telescope Quasar Absorption Lines Key Project. In addition, Bahcall was quite famous for his work on solar neutrinos, and was known as "The Godfather of Neutrinos." It is rare to be a giant contributor in one field, but Bahcall achieved that stature in two very different fields. He was a prolific scientist, having published over 600 refereed journal papers and nine books. His long list of awards and prizes includes the Gold Medal of the Royal Astronomical Society, the Fermi Award, the National Medal of Science, the Heineman Prize, and a NASA Distinguished Public Service Medal, and the Exceptional Scientific Achievement Award (posthumous). Bahcall lived to be 70 years old.

Wal Sargent

Wal Sargent spent most of his career at Caltech. By many, he was considered to be the "father of quasar absorption line surveys." He led the second Palomar Sky Survey, which imaged ~50 millions galaxies. Sargent also took sevral lead roles in the developent of the W.M. Keck Observatory. He famously told the builder of the HIRES instrument, Steven Vogt, to  design a "Quasar Eating Machine." Over the years, Sargent accumulated 100s of HIRES/Keck spectra (Wal's Vault) and mentored a string of Hubble Fellows to push the boundaries of our science. He was a Fellow of the American Academy of Arts and Sciences, a Fellow of the Royal Society, and a member of the National Academy of Sciences. Among other recognitions, he was awarded the Warner Prize, delivered an honorary Darwin Lecture to the Royal Astronomical Society, and received Heineman Prize and the Bruce Medal. Sargent lived to be 77 years old.

Art Wolfe

Art Wolfe was the Chancellor’s Associates Chair of Physics at UC San Diego. Over the span of his career he worked at the University of Cambridge, the Lebedev Physical Institute in Moscow, and the University of Pittsburgh before becoming a Professor in the Physics Department at UC San Diego and later the Director of the Center for Space Science. He was a Fellow of the American Academy of Arts and Sciences and the American Association for the Advancement of Science. He was a Sackler Fellow at the University of Cambridge and a recipient of the prestigious Jansky Prize. His research explored and impacted so many areas, including Zeeman splitting at high redshift and excited ions as indicators of star formation, for example. Wolfe lived to the the age of 74.

Jacqueline Bergeron

Jaqueline Bergeron was a pioneer in establishing the connection between galaxies and metal absorption lines in quasar spectra. Her seminal paper with Patrick Biossé in 1991 is foundational to the field. Throughout her career, she worked at Cambridge (w/ James Feldon), Cornell University, (w/ Ed Salpeter) Caltech (w/ Wal Sargent and Marteen Schmidt). She spent most of her career at the Institut d'Astrophysique de Paris. She served as the Director of ESO, and as General Secretary of  IAU. She was inducted into France's most prestigious order, the Légion d’Honneur, for her sceintific contributions. Bergeron lived to be 82 years old.

(Oct 15, 1909 - Oct 21, 2002). American astronomer Jesse Greenstein (Carnegie Observatories) was a close collaborator of Marteen Schmidt, Allan Sandage, and Tom Bolton at Caltech. He was part of the small elite group of astronomers that wrestled with the nature of emissions lines observed in the very first quasar spectrum of 3C 48. In a 1964 paper, Greenstein and Schmidt proposed that quasars must be  supermassive compact objects fueled by intense gravitational infalling gas. 

Notable students: Helmut Abt

American astronomer Thomas Matthews (Caltech) is credited, along with Alaln Sandage and John Bolton. with being one of the discoverers of the very first quasi-setllar object, 3C 48. In 1960, we was a prime observer using  the newly commissioned Owens Valley interferometer built by John Bolton. 

Notable students: Richard Tully

(Feb 11, 1911 - Jun 13, 1960) American astronomer Carl Seyfert was a student of the famous Harlow Shapley. Seyfert is best known for his pioneering studies of emission line galaxies in the 1940s. He essentially was the first to study and classify AGN (which would soon be called radio galaxies). Today, this class of galaxies bear his name. His life was tragically cut short by an auto accident. Ken Kellerman (one of  John Bolton's students) has speculated as to how the course of the discovery quasars and the circuitous path to the realization they were high-redshift objects may have been shortened had Seyfert lived through the next decade.

(Jun 26, 1914 - Mar 31, 1997) American astrophysicists Lyman Spitzer (Princeton) made countless significant contributions to physics, astrophysics, and engineering. He was first to propose that hot diffuse gas was present around galaxies. As early as 1948,  Spitzer proposed space telescopes to access the high-ionization ultraviolet absorption lines in bright background stars (quasar  would not be discovered for another 17 years!).  With Jon Rogerson and Don York, Spitzer was involved with the Copernicus space telescope to measure the first OVI absorption in the ISM of the Galaxy. 

Notable students: Carl Heiles, Bev Oke, and Leonard Searle.

British astronomer Alex Boksenberg (a.k.a. Boskey, Cambridge University) is credited with breaking the field of quasar spectroscopy wide open in the 1970s with his highly sensitive high-resolution Image Photon Counting System (ICPS).  It was highly sensitive with a linear response and no read noise. It boasted a resolution of 0.2 Å (12 km/s)!  In collaboration with Wal Sargent, Boksey engaged in research ranging from MgII and CIV surveys to galaxy halo studies. In 2015, he authored the seminal work on CIV and SiIV kinematics at z~3.5 using the HIRES/Keck spectrograph. 

Notable students: Erik Stengler

British astronomer Bob Carswell (Univ. of Sussex) is the primary author of the workhorse spectral fitting routine VPFIT (w/ John Webb). He pioneered Voigt profile fitting of both Lyman-alpha and metal-line absorbers in early (pre-Keck/VLT) high-resolution spectra. With Ray Weymann and Dennis Walsh, he is credited with identifying and studying  the the spectra of the first lensed quasar pair. Carswell is also a co-author on 1981 seminal Annual Review article. "QSO Absorption Lines in the Spectra of Quasi-Stellar objects." 

Notable students: Michael Rauch, John Webb, and Gerry Williger

American astronomer James Gunn (Princeton), while still in graduate school at Caltech i 1965, proposed the Gunn-Peterson (GP) Effect, which was observed 35 years later. The GP trough has been a key to understanding the Epoch of Reionization. Gunn conceived the Sloan Digitial Sky Survey (SDSS) and led efforts to bring it to fruition. Four-color selection was a key design component and SDSS was instrumental in finding some million high-redshift quasars, which forever transformed the field of quasar absorption lines.

Notable students: Augustus Oemler, Paul Schechter, and Don Schneider

(Jul 7, 1941 - Jul 19, 2022) American astronomer Blair Savage (Univ. of Wisconsin, Madison) is notable for his work on the Galactic ISM, corona, and CGM, including high-velocity clouds (HVCs) and the Magellanic Stream. He broke new ground with every new space telescope (OAO-2, Copernicus, IUE, FUSE, and HST), and was primary member of the HST QSO Absorption Line Key Project. Savage was a prolific scientist , having contributed to more then 550 journal articles. 

Notable students: Andrew Fox, Chris Howk, Ken Sembach, and Todd Tripp

British-born astronomer Peter Strittmatter (Univ. of Arizona) is best known for classification of quasars via study of peculiar spectral features. He proposed the class known as BL Lacertae Objects. In the early days, Strittmatter strongly argued that all quasar absorption lines were "intrinsic." meaning associated with the quasar environment. He lost that debate. He conducted early surveys of MgII and CIV and found an ionization proximity effect around quasars.

Notable students: Bradley Peterson.

American astronomer Ray Weymann (Carnegie Observatories) is highly recognized as the primary author of the 1981 Annual Review  "Absorption Lines in the Spectra of Quasi-Stellar Objects," which was the foundational work for two generations of astronomers. During his active career, he was a prolific and versatile quasar absorption line astronomer- his work ranged from metal-line surveys to gravitational lenses, to the nature of galaxy halos  He was a primary mmber of the HST Quasar Absorption Line Key Project, through which he characterized the evolution of the z<1.6 Lyman-alpha forest. 

Notable students: Todd Boroson, and David Turnshek.

(1944 - Dec 26, 2025) American astronomer Don York (Univ. of Chicago) is a giant in the field of ISM studies and quasar absorption lines. He is a member of the first team to measure D/H and  OVI absorption in the Milky Way (w/ Jon Rogerson) using the revolutionary Copernicus satellite. He is a co-founder of SDSS and originator of the SDSS quasar catalog. He steadfastly challenged the notion of a single monolithic gas halo around galaxies, thus foreshadowing the baryon cycle and its various infalling and outflowing components. 

Notable students: Jim Lauroesch, Gordon Richards, and Dan Vanden Berk.

Frank Briggs pioneered radio-band 21-cm absorption in the spectra of quasars. He opened the door to probing the CNM and the WNM in HI absorption the ISM of high-redshift galaxies. He clearly established that the neutral ISM gas resides in a two-phase medium and in BAL quasar winds. His work has since been built on and comprehensive deep redshift path surveys of 21-cm absorbers have been conducted out to the very high redshifts. Future work will likely observed redshift drift and absorption agains the CMB.

Notable students: Wendy Lane, Sandhya Rao, and Martin Zwaan

American astronomer Fred Chaffee (SAO) contributed foundation insights into a broad range of quasar science. He is known for pushing high-resolution observations to their very limit before 10-meter class telescopes made it routine. He was first to resolve the Lyman-alpha forest and constrain the physical conditions of IGM clouds. He use gravitational lenses to constrain the sizes of metal-line absorbers, and was prolific in the field of BAL quasars studies, and constrained their frequency. He was an early pioneer of D/H studies.  Chaffee rounded out his career by servinfgas Directory of the W.M. Keck Observatory.

Scotland-born British astronomer Len Cowie (Univ. of Hawaii) is highly notable for his work on quasar absorption line systems observed with HIRES/keck. He has studied the evolution of the Lyman-alpha forest (with Ester Hu), early-epoch D/H, DLAs, and metal-enrichment evolution (including proving that the Lyman-alpha forest was not "pristine.") He conducted some of the very first observations characterizing the Epoch of HI Reionization (w/ Antoinette Songaila).

Notable students: Jiasheng Huang, Li-Yen Hsu

American astronomer Bradley Peterson (Ohio State) was a student of Peter Strittmatter. He pioneered the technique of reverberation mapping of quasars to measure black hole masses. It was through his sustained effort over years that he proved the method to the astronomical community. Peterson is considered the "Father" of the field. An expert on AGN, he also authored the book An Introduction to Actice Galactic Nuclei. He led the International AGN Watch, the first campaign to collect uniform high quality data on AGN. He was awarded the NASA Exceptional Service Medal for his work on NASA's Advisory Coonil's Advisory Committee.

Notable students: Mike Crenshaw, Tim Korista, and Catherine Grier

Italian-born astronomer Max Pettini (Cambridge University) is renown for his research on the chemical evolution of galaxies, the intergalactic medium, D/H measurements, and high-redshift galaxies. He is a Fellow of the Royal Society (2010) and received the Herschel Medal from the Royal Astronomical Society (2008.) Pettini recently received the Gruber Cosmology Prize with Ryan Cooke for precision D/H measurements. 

Notable students: Ryan Cooke, Sara Ellison, Anna Quidar

American astronomer Don Schneider (Penn State) was a stduent of James Gunn (of the Gunn-Peterson Effect). As part of the HST Quasar Absorption Line Key Project, Schneider developed objective absorption line detection algorithms that remain state of the art. He is renown for his pioneering use of color selection to find z>4 quasars, which paved the way for finding quasars up to z~10.  Schneider has also contributed to studies of large scale structure and our understanding of extragalactic black holes. 

Notable students: Jianjian Shen

American astronomer Mike Shull (UC Boulder) is known for his breakthrough studies of the baryon budget of  WHIM gas .At Boulder, he and collaborator John Stocke participated in the design and building of the COS instrument. They built a team of AGN/quasar absorption line researchers with which they did pioneering and highly thorough  measurements of the properties of the z<0.4 IGM. 

Shull has several notable students, including (but not limited to) Charles Danforth, and Jason Tumlinson

American astronomer Bev Wills  (Univ. of Texas, Austin) is known for her long standing contributions and body of work in the field of AGN and quasars. She was instrumental in identifying the class of radio-quiet blazars, a subclass of active galaxies where the relativistic jet of ionized matter is directed almost directly toward the observer. She has extensively studied the broad absorption lines (BAL) quasars and has been instrumental in building insight into their black hole "engines," structure, and variability.

Notable students: Feng Ma, and Michael Brotherton.

(Jul 31, 1954 - Sep 5, 1981) British-born astrophysicist Peter Young was a brilliant researcher who died tragically while a postdoc at Caltech. He had recently finished his PhD under Wal Sargent at Caltech. which he accomplished in an amazing short 18 months. His few papers in the early 1980s wrote the book on how to undertake and analyze a uniform unbiased survey of a population of absorbers. Literally, all work in the field of quasar absorption lines since the early-1980s has deep roots in the methodologies he developed and pioneered.

(??? - Jan 12, 2024) American astronomer Jill Bechtold (Univ. of Arizona) conducted large surveys of Lyman-alpha absorption using HST; she built the VizieR HST/FOS Spectral Atlas known as the "Bechtold Catalog." She pioneered studies of the low-redshift Lyman-alpha forest and proximity effect to measure the UV background spectrum. Bechtold also did early ground-breaking work on the kinematics of strong metal-line absorbers

Notable students: Jennifer Scott.

French astronomer Patrick Biossé (Institut d'Astrophysique de Paris) was co-author on the seminal 1991 paper with Jaqueline Bergeron that established MgII absorbers arise in the halos of galaxies. His absorption line work included metal lines, Lyman-alpha forest ines, and DLAs. He was an early adopter of ionization modeling to gain insights into the chemical and ionization conditions of absorbing gas, especially small sub-parsec gas structures. Biossé participated in studies searching for time variations in intervening narrow metal-line absorbers at high redshifts. 

American astronomer Craig Foltz (MMT Observatory) was a leading researcher who was instrumental in characterizing radio and optical properties of quasars. He was an important contributor to the seminal Large Bright Quasar Survey (LBQS), which was one of the first surveys to characterize the overall quasar population. He also conducted impactful and influential studies of BAL absorption and metal-line absorption, such a MgII and CIV. Foltz served as Directory of the MMT Observatory, Program Manager for ALMA, and then Astronomical Sciences Acting Deputy Division Director for the NSF.

American astronomer Fred Hamann (UC Riverside) is a a leading expert on the broad absorption line (BAL) outflows of quasars. Using high-resolution spectra, he pioneered methods of analysis to study the complex nature of numerous BAL quasars, including their ionization, gas phases, metallicities, covering factors, and evolution. He is credited for the discovery of Extremely Red Quasars (ERQs) in the SDSS database. 

Notable students: Chen Chen,  and Paolo, Rodríguez Hidalgo

Antoinette Songaila (Univ. of Hawaii) engagd in ground-breaking work using HIRES/Keck to measure the column density distribution functions and gas mass densities of CIV and SiIV absorbers. She introduced her "super-POD" method, which used flux-decrement distributions of individual pixels. She explored the effects of HeII ionization in the IGM at z=3-4 and partook in early studies of the early-epoch D/H ratio.  

British-born astronomer David Tyler (UC San Diego) is primarily known for his meticulous measurements of the D/H ratio at high redshifts for placing constraints on the cosmic baryon mass density. His early work characterized the properties of Lyman-limit systems (LLS) as well as established their importance astrophysically. 

Notable students: Scott Burles, David Kirkman, and John O'Meara

American astronomer David Turnshek (Univ .of Pittsburgh) is well known for his early breakthrough work on BAL quasars. He and his primary collaborator Sandya Rao pioneered efficient methods to select for z<1 DLAs using MgII/FeII absorption and studied the z<1 HI mass density and nature (morpologies, luminosities, etc.) of DLA-selected galaxies.  

Notable students: Dan Nestor

American astronomer Meg Urry (Yale) is best known for championing unification models of AGN, studies of the role of black holes in the evolution of galaxies, and for her leadership and body of work supporting women in the sciences.  In all three areas she has had significant impact on the science and on the culture of science. She had received dozens of professional awards over her career.

Notable students: Arita Ghosh, and Matthew O'Dowd (yes, that Matt O'Dowd from PBS Spacetime).

British astronomer John Webb (Univ. of New South Wales) is best known for his breakthrough "many-multiplet" analysis methods for studying the evolution of the fine-structure constant using quasar absorption lines. He has also played a large role in the development of VPfit.  Webb was highly involved in the flurry of D/H ratio measurements being conducted in the 1990s. 

Notable students: Neil Crighton, and Michael Murphy

American astronomer Jane Charlton (Penn State) was a child prodigy who earned her B.S, in Physics and Chemistry at the age of 18. In her early career, she is known for her theoretical work with Ed Salpeter. Transitioning into the 1990s, Charlton began experimenting with multi-phase ionization modeling of absorbers and over the years has pioneered techniques to extract the detailed cloud-by-cloud densities, temperatures, kinematics, and metallicities. Her work was foundational leading to Bayesian inference and MCMC methods (w/ Sameer) that have yielded significant insights into metal-line absorbers and the CGM.

Notable Students: Ragib Ganguly, Anand Naryanan, and Jane Rigby

American astronomer Ken Lanzetta (SUNY Stoneybrook) was a student of Art Wolfe and worked with David Turnshek. In his early career, Lanzetta studied MgII absorbers and DLAs. In a series of papers in the mid-1990s, he established the HI extent of galaxy halos using Lyman-alpha absorbers  He had written the first modern notes on Quasar Absorption Lines for graduate classes. In his later career, Lanzetta became involved in private ventures and remains active using the Condor Array Telescope to image filaments in the cosmic web. 

Notable students: Hsiao-Wen Chen.

American astronomer Karen Leighly (Univ. of Oklahoma) is recognized for her work on the X-ray variability of narrow-line Seyfert galaxies and extensive research on the nature of broad absorption lines (BALs). She has developed the state-of-the-art spectral synthesis code SimBAL, which is capable of forward modeling using Bayesian "calibration" and MCMC to constraint the physical conditions of BALs. Coupled with her use of infrared spectroscopy, she has learned how to penetrate deep into these winds and extract accurate column densities, gas densities, and ionization states. 

French astronomer Patrick Petitjean (Institut d'Astrophysique de Paris) is well known for his work on MgII, CIV, and DLA systems.  He has advanced research in the areas of high-resolution studies of the IGM, precision spectroscopy to verify the constancy of the fine-structure constant, and absorption line measurements of the temperature of the CMB in the early universe. Petitjean often collaborated with Jaqueline Bergeron. 

Notable Students: Cédric Ledoux, Bastian Aracil, and Pasquier Noterdaeme.

American astronomer Ken Sembach (STScI) was a student of Blair Savage. He was a past Director of STScI and Deputy Project Scientists for the Far Ultraviolet Spectroscopic Explorer (FUSE). He pioneered ultraviolet absorption line spectroscopy (SiIV, CIV, OVI and NV) of the diffuse ISM and CGM gas in the Milky Way galaxy. In colaboration with Blair Savage, Sembach was instrumental in early characterizations of the chemical composition, kinematics, and ionization conditions of Galactic gas.

American astronomer Chuck Steidel (Caltech) was a student of the late great Wal Sargent. Steidel is known for early large absorption lines surveys of MgII and CIV, and LLS absorber classes. He is well known for his work establishing the sizes and kinematics of galaxy halos using MgII absorbers. In the mid-1990s, Steidel broke open the redshift 2.5 universe using Lyman Break Galaxies. He is PI of the highly successful Keck Baryonic Structure Survey. 

Steidel has several notable students including (but not limited to) Dawn Erb, Gwen Rudie, and Alice Shapley.