Tahir Yaqoob
(RESEARCH SCIENTIST)
| Email: | tahir.yaqoob-1@nasa.gov |
| Phone: | 301.286.5015 |
| Org Code: | |
| Address: |
NASA/GSFC Mail Code 662 Greenbelt, MD 20771 |
| Employer: | UMBC Univ. of MD, Baltimore County |
Brief Bio
Dr. Tahir Yaqoob obtained a bachelor's degree in physics from the University of Oxford, UK, in 1986, and a PhD in X-ray astrophysics from the University of Leicester, UK, in 1990. He is a senior research scientist affiliated with the University of Maryland Baltimore Country (UMBC), and the Center for Research and Exploration in Space Science and Technology (CRESST II), specializing in the area of X-ray astrophysics, with more than 40 years in the field. Dr. Yaqoob is currently a member of the XRISM Science Data Center (SDC), specializing in the design of some of the data analysis tools and X-ray telescope raytracing simulator. Dr. Yaqoob has been a member of the Science Team for a number of X-ray astronomy missions (ASCA, Astro-E, Astro-E2 (Suzaku), Hitomi, XRISM), serving in various roles. Dr. Yaqoob's most active areas of research concern X-ray observations and theoretical modeling of physical processes, and the inflows and outflows in accreting black-hole systems, from the extreme conditions in the vicinity of the black hole, out to the parsec-scale circumnuclear environment. Research areas include X-ray diagnostics of black-hole spin and improvement of the robustness of spectral deconvolution from distant-matter spectral components; development and applications of techniques to separate the global and line-of-sight column densities in X-ray sources; physics of Active Galactic Nuclei (AGN), starburst galaxies, quasars, and blazars (including TeV observations); X-ray and UV absorption and photoionized outflows and inflows in AGN and quasars; high spectral-resolution X-ray spectroscopy; X-ray power spectra, spectral and temporal variability; AGN unification; Cosmic X-ray background; coordinated multi-wavelength and multi-mission monitoring campaigns of AGN; clusters of galaxies; absorption in the warm/hot intergalactic medium (WHIGM); statistics; data analysis methods; numerical and Monte-Carlo modeling of astrophysical processes; X-ray optics, raytracing, and deconvolving spatial-spectral mixing in extended X-ray sources. Dr. Yaqoob also has decades of experience teaching and mentoring physics, math, and astronomy, from pre-undergraduate to Ph.D. and post-doctoral levels.
Research Interests
Modeling physical processes in accreting black-hole and compact object systems
Astrophysics: X-ray AstrophysicsX-ray optics, raytracing
Astrophysics: X-ray AstrophysicsCurrent Projects
Senior Research Scientist, XRISM Science Data Center (SDC)
Analysis
Design, validation testing, and oversight of development XRISM data analysis tools.
XRISM Calibration Data Base (CalDB) lead
Analysis
Ingest of calibration constituents, prototyping, validation testing, contributions to ground and inflight calibration.
XRISM Data Analysis
X-ray Astrophysics
Analysis and interpretation of XRISM data on various astrophysical sources.
XRISM Data Analysis Methods for Extended Sources
X-ray Astrophysics
Development and documentation for techniques and methodologies to analyze XRISM data for extended sources, accounting for the broad point-spread function of the XRISM telescopes.
"MYTORUS" Model for X-ray Reprocessing in Active Galactic Nuclei (AGN)
Theory & Modeling
Development and maintenance of the MYTORUS model of X-ray reflection and Fe K line emission for spectral fitting of X-ray spectra of AGN.
Raytracing X-ray Optics Simulations of Thin-Foil X-ray Telescopes
Theory & Modeling
Development, validation testing, and maintenance of raytracing model for the Hitomi and XRISM X-ray telescopes; analysis of results of raytracing simulations, including diagnostics for calibration.
"Quick-Start Guide" for XRISM Data Analysis
Analysis
Lead on the "Quick-Start Guide" for XRISM Data Analysis. Ongoing updates and maintenance.
Positions/Employment
Royal Society/JSPS Postdoctoral Fellowship
Institute of Space and Astronautical Science - Sagamihara, Kanagawa, Japan
August 1990 - September 1991
Royal Society/JSPS Postdoctoral Fellowship
Institute of Astronomy - Cambridge, UK
October 1991 - September 1992
Research Scientist
USRA - NASA/Goddard Space Flight Center, MD, USA
October 1992 - April 2000
Research Scientist
University of Maryland Baltimore Country (UMBC) - Maryland, USA (located at GSFC)
May 2000 - September 2000
Principal Research Scientist
Johns Hopkins University - Baltimore, USA
October 2000 - May 2013
Senior Research Scientist
University of Maryland Baltimore Country (UMBC) - Maryland, USA (located at GSFC)
May 2013 - Present
Teaching Experience
Undergraduate & Graduate level Physics, Astrophysics, Mathematics, Astrophysics
PhD & post-doctoral supervision & mentoring
Special Lecture Series -
"Eight Unsolved Mysteries of the Universe" (JHU)
"The Universe at High Energies" (JHU) (Graduate level)
MCAT Physics (JHU)
Education
Tahir Yaqoob obtained a B.A. (Hons) in Physics at the University of Oxford, UK, in 1986, and a PhD in X-ray Astrophysics at the University of Leicester, UK, in 1990. He subsequently continued his research in X-ray astronomy at the Institute of Space and Astronautical Science (ISAS), Japan, on a Royal Society/JSPS Fellowship, and then at the Institute of Astronomy, Cambridge, UK, on a Royal Society Fellowship.
Professional Service
Refereeing of journal papers, served on proposal review panels for various X-ray astronomy missions, technical support for proposal review panels.
Awards
Japan Society for the Promotion of Science (JSPS) fellowship 1990-1991
Royal Society (UK) fellowship, 1991-1992
ASCA Special Act, Group Award, October 1993
ASCA Mission Operations Team, Group Award, May 1996
Special Experience
PI & Director of JHU/GSFC Cooperative Agreement, 2004-2008 (budget >$1M/year).
PI of research proposals totaling >$2.2M.
Chair of Science Organizing Committee for international conference "X-ray Emission from Accretion onto Black Holes" JHU, June 2001,
Member of organizing committee for IAU Symposium #238, "Black Holes - from Stars to Galaxies", Prague, 2006.
Selected Publications
Refereed
2026. "XRISM Spectroscopy of a Crowded Galactic Center Region. II. Narrow Emission Lines in the Black Hole Candidate MAXI J1744-294/Swift J174540.2-290037.", The Astrophysical Journal, 1006 (2): 152 [10.3847/1538-4357/ae77f5] [Journal Article/Letter]
2025. "XRISM Reveals Complex Ionization and Velocity Structures in the GX 340+0 X-Ray Binary.", The Astrophysical Journal, 991 (2): 224 [10.3847/1538-4357/adfb65] [Journal Article/Letter]
2025. "XRISM pre-pipeline and Singularity: container-based data processing for the X-ray imaging and spectroscopy mission and high-performance computing.", Journal of Astronomical Telescopes, Instruments, and Systems, 11 (04): [10.1117/1.jatis.11.4.042013] [Journal Article/Letter]
2023.
"Ubiquity and magnitude of large
2023. "Incorporation of realistic intrinsic profiles for the Fe Kα and Fe Kβ emission lines in X-ray reprocessor models.", Monthly Notices of the Royal Astronomical Society, 527 (1): 1093-1100 [10.1093/mnras/stad3257] [Journal Article/Letter]
2023. "NGC 4388: a test case for relativistic disc reflection and Fe K fluorescence features.", Monthly Notices of the Royal Astronomical Society, 522 (1): 394-411 [10.1093/mnras/stad782] [Journal Article/Letter]
2021. "Are Compton-thin AGNs Globally Compton Thin?.", The Astrophysical Journal, 922 (1): 85 [10.3847/1538-4357/ac1ff6] [Journal Article/Letter]
2018. "Spectral response and effective area functions of the Hitomi imaging instruments.", Journal of Astronomical Telescopes, Instruments, and Systems, 4 (04): 1 [10.1117/1.jatis.4.4.048005] [Journal Article/Letter]
2018. "New Constraints on the Geometry and Kinematics of Matter Surrounding the Accretion Flow in X-Ray Binaries from Chandra High-energy Transmission Grating X-Ray Spectroscopy.", The Astrophysical Journal, 855 (1): 25 [10.3847/1538-4357/aaaab6] [Journal Article/Letter]
2016. "No signatures of black hole spin in the X-ray spectrum of the Seyfert 1 galaxy Fairall 9.", Monthly Notices of the Royal Astronomical Society, 462 (4): 4038-4054 [10.1093/mnras/stw1824] [Journal Article/Letter]
2015. "A Compton-thin solution for the Suzaku X-ray spectrum of the Seyfert 2 galaxy Mkn 3.", Monthly Notices of the Royal Astronomical Society, 454 (1): 973-990 [10.1093/mnras/stv2021] [Journal Article/Letter]
2012. "The nature of the Compton-thick X-ray reprocessor in NGC 4945.", Monthly Notices of the Royal Astronomical Society, 423 (4): 3360-3396 [10.1111/j.1365-2966.2012.21129.x] [Journal Article/Letter]
2011. "The energy budget for X-ray to infrared reprocessing in Compton-thin and Compton-thick active galaxies.", Monthly Notices of the Royal Astronomical Society, 412 (2): 835-842 [10.1111/j.1365-2966.2010.17942.x] [Journal Article/Letter]
2011. "Monte Carlo simulations of the nickel Kα fluorescent emission line in a toroidal geometry.", Monthly Notices of the Royal Astronomical Society, 412 (3): 1765-1770 [10.1111/j.1365-2966.2010.18012.x] [Journal Article/Letter]
2010. "The Compton shoulder of the Fe Kα fluorescent emission line in active galactic nuclei.", Monthly Notices of the Royal Astronomical Society, 412 (1): 277-286 [10.1111/j.1365-2966.2010.17902.x] [Journal Article/Letter]
2010. "NGC 2992 in an X-ray High State Observed by XMM-Newton: Response of the Relativistic Fe Kα Line to the Continuum.", The Astrophysical Journal, 713 1256 [Full Text] [10.1088/0004-637X/713/2/1256] [Journal Article/Letter]
2010. "The Cores of the Fe Kα Lines in Active Galactic Nuclei: An Extended Chandra High Energy Grating Sample.", The Astrophysical Journal Supplement, 187 581 [Full Text] [10.1088/0067-0049/187/2/581] [Journal Article/Letter]
2010. "On the efficiency of production of the Fe Kα emission line in neutral matter.", Monthly Notices of the Royal Astronomical Society, 401 411 [Full Text] [10.1111/j.1365-2966.2009.15657.x] [Journal Article/Letter]
2010. "Evidence for ultra-fast outflows in radio-quiet AGNs I Detection and statistical incidence of Fe K-shell absorption lines.", Astronomy and Astrophysics, 521 57 [Full Text] [10.1051/0004-6361/200913440] [Journal Article/Letter]
2009. "On the Prospect of Constraining Black Hole Spin Through X-ray Spectroscopy of Hotspots.", The Astrophysical Journal, 701 635 [Full Text] [10.1088/0004-637X/701/1/635] [Journal Article/Letter]
2009. "An X-ray spectral model for Compton-thick toroidal reprocessors.", Monthly Notices of the Royal Astronomical Society, 397 1549 [Full Text] [10.1111/j.1365-2966.2009.15025.x] [Journal Article/Letter]
2007. "Precision Fe Kα and Fe Kβ Line Spectroscopy of the Seyfert 19 Galaxy NGC 2992 with Suzaku.", Publications of the Astronomical Society of Japan, Vol59, NoSP1, pp283-299, 59 283 [Full Text] [Journal Article/Letter]
2007. "A soft X-ray study of type I active galactic nuclei observed with Chandra high-energy transmission grating spectrometer.", Monthly Notices of the Royal Astronomical Society, 379 1359 [Full Text] [10.1111/j.1365-2966.2007.11993.x] [Journal Article/Letter]
2007. "Monitoring the Violent Activity from the Inner Accretion Disk of the Seyfert 19 Galaxy NGC 2992 with RXTE.", The Astrophysical Journal, 666 96 [Full Text] [10.1086/520039] [Journal Article/Letter]
2005. "Iron K Features in the Quasar E1821+643: Evidence for Gravitationally Redshifted Absorption?.", The Astrophysical Journal, 623 112 [Full Text] [10.1086/428432] [Journal Article/Letter]
2004. "The Cores of the Fe K Lines in Seyfert 1 Galaxies Observed by the Chandra High Energy Grating.", The Astrophysical Journal, 604 63 [Full Text] [10.1086/381731] [Journal Article/Letter]
2004. "An Extended Scheme for Fitting X-Ray Data with Accretion Disk Spectra in the Strong Gravity Regime.", The Astrophysical Journal Supplement Series, 153 205 [Full Text] [10.1086/421115] [Journal Article/Letter]
2003. "Fe XXV and Fe XXVI Diagnostics of the Black Hole and Accretion Disk in Active Galaxies: Chandra Time-resolved Grating Spectroscopy of NGC 7314.", The Astrophysical Journal, 596 85 [Full Text] [10.1086/377687] [Journal Article/Letter]
2002. "The Effect of Changes in the ASCA Calibration on the Fe K Lines in Active Galaxies.", The Astrophysical Journal, 569 487 [Full Text] [10.1086/339166] [Journal Article/Letter]
2001. "Physical Diagnostics from a Narrow Fe Kα Emission Line Detected by Chandra in the Seyfert 1 Galaxy NGC 5548.", The Astrophysical Journal, 546 759 [Full Text] [10.1086/318315] [Journal Article/Letter]
2001. "Quasi-periodic Oscillation in Seyfert Galaxies: Significance Levels The Case of Markarian 766.", The Astrophysical Journal, 562 L121 [Full Text] [10.1086/338252] [Journal Article/Letter]
2000. "A search for short-timescale TeV variability in Mrk421 and Mrk501.", Nuclear Physics B Proceedings Supplements, Vol 80, Proceedings of the Texas Symposium on Relativistic Astrophysics and Cosmology held in Paris, France, 14-18 December, 1998 CDROM contents, p01/03, 80 0103 [Full Text] [Journal Article/Letter]
2000. "A Broad Fe Kα Emission Line in the X-Ray Spectrum of the Quasar 3C 273.", The Astrophysical Journal, 544 L95 [Full Text] [10.1086/317318] [Journal Article/Letter]
1999. "A Highly Doppler Blueshifted Fe K Emission Line in the High-Redshift QSO PKS 2149−306.", The Astrophysical Journal, 525 (1): L9-L12 [10.1086/312327] [Journal Article/Letter]
1999. "X‐Ray Constraints on Accretion and Starburst Processes in Galactic Nuclei. I. Spectral Results.", The Astrophysical Journal Supplement Series, 120 (2): 179-208 [10.1086/313179] [Journal Article/Letter]
1999. "On the Unusually High Temperature of the Cluster of Galaxies 1E 0657−56.", The Astrophysical Journal, 511 (2): L75-L78 [10.1086/311842] [Journal Article/Letter]
1998. "A Peculiar Emission-Line Feature in the X-Ray Spectrum of the Quasar PKS 0637−752.", The Astrophysical Journal, 505 (2): L87-L90 [10.1086/311618] [Journal Article/Letter]
1998. "On the Evidence for Extreme Gravity Effects in MCG −6-30-15.", The Astrophysical Journal, 502 (2): L139-L142 [10.1086/311497] [Journal Article/Letter]
1998. "Occultation Mapping of the Central Engine in the Active Galaxy MCG −6-30-15.", The Astrophysical Journal, 501 (1): L29-L32 [10.1086/311457] [Journal Article/Letter]
1998. "Parameter Estimation in X‐Ray Astronomy Revisited.", The Astrophysical Journal, 500 (2): 893-898 [10.1086/305781] [Journal Article/Letter]
1997. "A Simple New Method for Analyzing Gapped Time Series: Search for a High-frequency Cutoff in the X-Ray Power Spectrum of the Seyfert Galaxy MCG −6−30−15.", The Astrophysical Journal, 490 (1): L25-L28 [10.1086/311014] [Journal Article/Letter]
1997. "X‐Ray Transmission in Cold Matter: Nonrelativistic Corrections for Compton Scattering.", The Astrophysical Journal, 479 (1): 184-189 [10.1086/303843] [Journal Article/Letter]
1997. "ASCA Observations of Seyfert 1 Galaxies. II. Relativistic Iron Kα Emission.", The Astrophysical Journal, 477 (2): 602-622 [10.1086/303721] [Journal Article/Letter]
1996. "Discovery of Rapid Variability of the Iron K-Line Profile in the Seyfert Galaxy NGC 7314.", The Astrophysical Journal, 470 (1): L27-L30 [10.1086/310297] [Journal Article/Letter]
1995. "The Hard X-Ray Emission of NGC 3628 and the Contribution of Low-Luminosity Spiral Galaxies to the Cosmic X-Ray Background.", The Astrophysical Journal, 455 508 [10.1086/176600] [Journal Article/Letter]
1993. "Is X1957 + 11 a black hole candidate?.", Monthly Notices of the Royal Astronomical Society, 264 (2): 411-420 [10.1093/mnras/264.2.411] [Journal Article/Letter]
1992. "Non-thermal pair models of the X-ray spectral index variability in NGC 4151.", Monthly Notices of the Royal Astronomical Society, 258 (1): 198-216 [10.1093/mnras/258.1.198] [Journal Article/Letter]
1989. "Variable X-ray absorption in NGC 4151.", Monthly Notices of the Royal Astronomical Society, 236 (2): 153-170 [10.1093/mnras/236.2.153] [Journal Article/Letter]