::: Sitemap Chinese Version中文 PrintPrint Friendly search help
People > Curriculum Vita
Accretion geometry of disks for LLAGN corresponding to low rate of mass accretion.
Accretion geometry of disks for LLAGN
Luminosity evolution of pulsar outer magnetospheric accelerators as a function of neutron star spin down luminosity. Two extreme chemical compositions of the neutron star envelopes are considered. The red curves correspond to a heavy element envelope, while the blue and black curves correspond to a light element envelope. The solid, dash-dotted, and dash-dot-dot-dot curves represent numerical solutions, while dashed and dotted ones represent analytical solutions. The circles, squares, and triangles designate the pulsars detected by the Fermi satellite: the green filled circles show the radio loud gamma-ray pulsars, while the blue filled squares show the radio quiet ones. From Hirotani 2013, ApJ, 766, 98.
Luminosity evolution of pulsar outer magnetospheric accelerators as a function of neutron star spin down luminosity.
Accretion geometry of disks for LLAGN (upper panel) and high luminosity AGN (lower panel) corresponding to high and low rates of mass accretion respectively. (Liu & Taam 2009, ApJ, 707, 233.)
Accretion geometry of disks for LLAGN and high luminosity AGN corresponding to high and low rates of mass accretion respectively.
Stellar density wave of the spiral galaxy M81. Left panel – Theoretical density distribution for a spiral mode. Middle panel – IRAC 3.6 micron map of the non-axisymmetric density distribution. Right panel – Comparison of observation with the theoretical model.
Stellar density wave of the spiral galaxy M81.
A comparison between the numerical simulation result and the observation of NGC 1097. Left panel: The projected surface density distribution of the simulation result. Middle panel: Optical image of NGC 1097 taken with the Visible Multi-Object Spectrograph (VIMOS) instrument on the 8.2-m Melipal (Unit Telescope 3) of ESO's Very Large Telescope. Right panel: Superposition of the left two figures. North is at the top and east is to the left.
HYDRODYNAMICAL SIMULATIONS OF THE BARRED SPIRAL GALAXY NGC 1097
Gas density in the orbital plane of a binary system in the common envelope evolutionary phase. Gas quantities are sampled along the black line (see ApJ 746, 74), revealing the presence of spiral shocks.
AMR Study of the Common Envelope Phase of Binary Evolution
The three panels show the results for three different wind speeds: 0, 5 and 10 Mach, with Mach the number of times the local sound speed is exceeded. The circle indicates the orbit of the planet or brown dwarf, with its current location at the intersection of the dotted lines. The dashed lines denotes the opening angle of the spiral in a static medium, from which the corresponding models with faster winds start their spiral pattern. The resulting density enhancement is indicated by the color scale.
Spiral density patterns calculated for the interaction between a dense stellar wind and a planet or brown dwarf orbiting the mass-losing star
Schematic picture of the truncated outer disk separated from the inner disk by a coronal gap, indicating the energy and mass flow in the configuration.
The Existence of Inner Cool Disks in the Low Hard State of Accreting Black Holes
The results suggest that neutron stars in systems characterized by low thermal X-ray luminosities (i.e., SAX J1808-3658 and 1H 1905+000) may be of high mass.
X-ray and Gamma-ray Emissions from Rotation Powered Millisecond Pulsars
It can be seen that the donor can reveal emission lines in the infrared region. Observations of both the continuum and lines in this wavelength region will provide important insight on the thermal state of the donor star and, hence, provide an observational test of the binary evolutionary history of these systems.
Theoretical Spectra of the AM CVn Binary System SDSS J0926+3624: Effects of Irradiation onto the Donor Star
The figures show the number of systems (color coded) for a degree of asymmetry, as measured by K, as a function of the orbital separation, luminosity, mass of the AGB star, and mass of its companion.
The Incidence of Non-spherical Circumstellar Envelopes in AGB Stars
A schematic view of binary system during the transition from the accretion powered low mass X-ray binary phase to the rotation powered millisecond radio pulsar phase.
On the Transition from Accretion Powered to Rotation Powered Millisecond Pulsars
The numerical solutions of a D2 disk for N=1024, the profiles are surface density (left-top), the x-directional force (right-top), the y-directional force(left-bottom), and radial force(right-bottom).
Self-gravitational force calculation of infinitely thin gaseous disks
The left panel corresponds to the particle image showing the face on and two edge on views of an initially axisymmetric disk. The right panel shows the formation of a bar which produces a peanut shaped morphology.
The Effect of Bars and Transient Spirals on the Vertical Heating in Disk Galaxies
Three dimensional hydrodynamical simulations show that the substellar mass objects produce detectable signatures, corresponding to density contrasts of 10--200 % and arm separations of 10--400 AU at 100 AU distance, for the wake induced by a Jupiter to brown dwarf mass object orbiting a solar mass AGB star.
Probing Substellar Companions of Asymptotic Giant Branch Stars through Spirals and Arcs
Observations of SNIa rates as a function of redshift suggest the existence of a short delay time population of 100 Myr and a long delay time population of 3-4 Gyr.
Impact of Type Ia Supernova Ejecta on a Helium Star Binary Companion
Taam, Ronald E.
Distinguished Research Fellow (Retired)
photo of Taam, Ronald E.
Email: r-taam_replace2@_northwestern.edu

Education and Positions

  • Professor Emeritus, Department of Physics and Astronomy, Northwestern University (2012~present)
  • Distinguished Research Fellow, ASIAA (2010~2018)
  • Chairman, Department of Physics and Astronomy, Northwestern University (1995~1998)
  • Professor, Department of Physics and Astronomy, Northwestern University (1986~2012)
  • Associate Professor, Department of Physics and Astronomy, Northwestern University (1983~1986)
  • Assistant Professor, Department of Physics and Astronomy, Northwestern University (1978~1983)
  • Lecturer, Astronomy Department, UC Berkeley (1976~1978)
  • Postdoctoral Research Associate, Lick Observatory (1973~1976)
  • PhD, Columbia University (1973)

Research Interests

My research focuses on astrophysical hydrodynamics related to the formation and evolution of interacting binary systems and the structure and evolution of accretion disks surrounding compact objects. Specifically, efforts are directed toward understanding the nature of stellar X-ray sources as well as the nature of active galactic nuclei.

Journal Papers affiliated with ASIAA

  1. Kim H; Liu S-Y; Taam RE, "Templates of Binary-induced Spiral-shell Patterns around Mass-losing Post-main-sequence Stars" , ApJS: 243(2), id. 35 (44 pp.), Aug, 2019 [SCI] ( ADS | Fulltext )
  2. Mösta P; Taam RE; Duffell PC., "Gas Flows Within Cavities of Circumbinary Disks in Eccentric Binary Protostellar Systems" , ApJL: 875(2), id. L21 (6 pp.), Apr, 2019 [SCI] ( ADS | Fulltext )
  3. Garcia-Segura G; Ricker PM; Taam RE, "Common Envelope Shaping of Planetary Nebulae" , ApJ: 860(1), 19, June, 2018 [SCI] ( ADS | Fulltext )
  4. Taam RE; Qiao E; Liu BF; Meyer-Hofmeister E, "A Model for Spectral States and Their Transition in Cyg X-1" , ApJ: 860(2), id. 166 (5 pp. ), June, 2018 [SCI] ( ADS | Fulltext )
  5. Wu Y-T; Pfenniger D; Taam RE, "Time Dependent Pattern Speeds in Barred Galaxies" , ApJ: 860(2), id. 152 (22 pp.), June, 2018 [SCI] ( ADS | Fulltext )
  6. Yi S-X; Cheng KS; Taam RE, "The Growth of Stellar Mass Black Hole Binaries Trapped in an Accretion Disk of Active Galactic Nuclei" , ApJL: 859(2), L25, June, 2018 [SCI] ( ADS | Fulltext )
  7. Kim H; Trejo A; Liu S-Y; Saha R; Taam RE; ...; Hirano N; et al., "The large-scale nebular pattern of a superwind binary in an eccentric orbit" , Nature Astronomy: 1, 0060, March, 2017 [SCI] ( ADS | Fulltext )
  8. Liu BF; Taam RE; Qiao E; Yuan W, "Centrally Concentrated X-Ray Radiation from an Extended Accreting Corona in Active Galactic Nuclei" , ApJ: 847(2), 96, Oct 1, 2017 [SCI] ( ADS | Fulltext )
  9. Kim H; Liu S-Y; Hirano N; Zhao-Geisler R; Trejo A; Yen H-W; Taam RE; Kemper F; et al., "Spiral-shells and nascent bipolar outflow in CIT 6: hints for an eccentric-orbit binary?" , J. Phys.: Conf. Ser.: 728(7), 072018, Oct, 2016 ( ADS | Fulltext )
  10. Wang H-H; Taam RE; Yen CC*, "Self-Gravitational Force Calculation of Infinitesimally Thin Gaseous Disks on Nested Grids" , ApJS: 224(2), 16, June, 2016 [SCI] ( ADS | Fulltext )
  11. Wu Y-T*; Pfenniger D; Taam RE, "Time-dependent Corotation Resonance in Barred Galaxies" , ApJ: 830(2), 111, Oct 20, 2016 [SCI] ( ADS | Fulltext )
  12. Kim H; Liu S-Y; Hirano N; Zhao-Geisler R; Trejo A; Yen H-W; Taam RE; Kemper F; et al ., "High-resolution CO observation of the carbon star CIT 6 revealing the spiral structure and a nascent bipolar outflow" , ApJ: 814(1), 61, Nov 20, 2015 [SCI] ( ADS | Fulltext )
  13. Lin L-H; Wang H-H; Hsieh P-Y; Taam RE; Yang C-C; Yen DCC, "Hydrodynamical simulations of the barred spiral galaxy NGC 1097" , Highlights of Astronomy: 16, 376-376, March, 2015 ( ADS | Fulltext )
  14. Liu BF; Taam RE; Qiao E; Yuan W, "A Hybrid Two Component Accretion Flow Surrounding Supermassive Black Holes in AGNs" , ApJ: 806(2), 223, June 20, 2015 [SCI] ( ADS | Fulltext )
  15. Pan K-C; Ricker PM; Taam RE, "Simulations of the Symbiotic Recurrent Nova V407 Cyg I. Accretion and Shock Evolutions" , ApJ: 806(1), 27, June 10, 2015 [SCI] ( ADS | Fulltext )
  16. Wang H-H; Lee W-K; Taam RE; Feng C-C; Lin L-H, "Spiral Density Waves in M81. II. Hydrodynamic Simulations of the Gas Response to Stellar Spiral Density Waves" , ApJ: 800(2), 106, Feb, 2015 [SCI] ( ADS | Fulltext )
  17. Wang H-H; Yen C-C; Taam RE, "Self-Gravitational Force Calculation of Second Order Accuracy for Infinitesimally Thin Gaseous Disks in Polar Coordinates" , ApJS: 221(1), 4, Nov, 2015 [SCI] ( ADS | Fulltext )
  18. Feng C-C; Lin L-H; Wang H-H; Taam RE, "Spiral Density Waves in M81. I. Stellar Spiral Density Waves" , ApJ: 785(2), 103, April, 2014 [SCI] ( ADS | Fulltext )
  19. Pan K-C; Ricker PM; Taam RE, "Search for Surviving Companions in Type Ia Supernova Remnants" , ApJ: 792(1), 71, Sept 1, 2014 [SCI] ( ADS | Fulltext )
  20. Ivanova N; Justham S; Chen X; ...; Taam R; et al., "Common Envelope Evolution: Where We Stand and How We Can Move Forward" , A&ARv: 21, 59, Feb 27, 2013 [SCI] ( ADS | Fulltext )
  21. Kiel P; Taam RE, "Accretion, Ablation and Propeller Evolution in Close Millisecond Pulsar Binary Systems" , Ap&SS: 348, 441-458, Dec, 2013 [SCI] ( ADS | Fulltext )
  22. Kim H; Hsieh I-T; Liu S-Y; Taam RE, "Evidence of a Binary Induced Spiral From an Incomplete Ring Pattern of CIT 6" , ApJ: 776(2), 86, Oct, 2013 [SCI] ( ADS | Fulltext )
  23. Lin L-H; Wang H-H; Hsieh P-Y; Taam RE; Yang C-C; Yen DCC, "Hydrodynamical Simulations of the Barred Spiral Galaxy NGC 1097" , ApJ: 771(1), 8, July, 2013 [SCI] ( ADS | Fulltext )
  24. Liu BF; Taam RE, "Constraints on the Viscosity and Magnetic Field in Hot Accretion Flows around Black Holes" , ApJS: 207(1), 17, July, 2013 [SCI] ( ADS | Fulltext )
  25. Pan K-C; Ricker PM; Taam RE, "Evolution of Post-impact Remnant Helium Stars in Type Ia Supernova Remnants within the Single-degenerate Scenario" , ApJ: 773(1), 49, Aug 10, 2013 [SCI] ( ADS | Fulltext )
  26. Saha K; Pfenniger D; Taam RE, "Meridional tilt of the stellar velocity ellipsoid during bar buckling instability" , ApJ: 764(2), 123, Feb 20, 2013 [SCI] ( ADS | Fulltext )
  27. Kim H; Taam RE, "Probing Substellar Companions of AGB Stars through Spirals and Arcs" , ApJ: 744(2), 136, Jan, 2012 [SCI] ( ADS | Fulltext )
  28. Kim H; Taam RE, "A New Method of Determining the Characteristics of Evolved Binary Systems Revealed in the Observed Circumstellar Patterns: Application to AFGL 3068" , ApJL: 759(1), L22, Nov, 2012 [SCI] ( ADS | Fulltext )
  29. Kim H; Taam RE, "Wide Binary Effects on Asymmetries in Asymptotic Giant Branch Circumstellar Envelopes" , ApJ: 759(1), 59, Nov 1, 2012 [SCI] ( ADS | Fulltext )
  30. Pan K-C; Ricker PM; Taam RE, "Impact of Type Ia Supernova Ejecta on Binary Companions in the Single-degenerate Scenario" , ApJ: 750(2), 151, May 10, 2012 [SCI] ( ADS | Fulltext )
  31. Pan K-C; Ricker PM; Taam RE, "Evolution of Post-Impact Companion Stars in SN Ia Remnants Within the Single-Degenerate Scenario" , ApJ: 760(1), 21, Nov 20, 2012 [SCI] ( ADS | Fulltext )
  32. Ricker PM; Taam RE, "An AMR Study of the Common Envelope Phase of Binary Evolution" , ApJ: 746(1), 74, Feb, 2012 [SCI] ( ADS | Fulltext )
  33. Taam RE; Liu BF; Yuan W; Qiao E, "Disk Corona Interaction: Mechanism for the Disk Truncation and Spectrum Change in Low-luminosity Active Galactic Nuclei" , ApJ: 759(1), 65, Nov 1, 2012 [SCI] ( ADS | Fulltext )
  34. Takata J; Cheng KS; Taam RE, "X-Ray and Gamma-Ray Emissions from Rotation Powered Millisecond Pulsars" , ApJ: 745(1), 100, Jan, 2012 [SCI] ( ADS | Fulltext )
  35. Yen DCC; Taam RE; Yeh HC; Jea KC, "Self-gravitational Force Calculation of Infinitesimally Thin Gaseous Disks" , JCP: 231(24), 8246-8261, Oct, 2012 [SCI] ( ADS | Fulltext )
  36. Lin L-H; Taam RE; Yen DCC; Muller S; Lim J, "The Central Region of the Nearby Seyfert 2 Galaxy NGC 4945: A Pair of Spirals" , ApJ: 731(1), 15, Apr 10, 2011 [SCI] ( ADS | Fulltext )
  37. Liu BF; Done C; Taam RE, "The Effect of Coronal Radiation on a Residual Inner Disk in the Low/Hard Spectral State of Black Hole X-ray Binary Systems" , ApJ: 726(1), 10, Jan 10, 2011 [SCI] ( ADS | Fulltext )
  38. Politano M; Taam RE, "The Incidence of Non-spherical Circumstellar Envelopes in Asymptotic Giant Branch Stars" , ApJ: 741(1), 5, Nov 1, 2011 [SCI] ( ADS | Fulltext )
  39. Sengupta S; Taam RE, "Theoretical Spectra of the AM Canum Venaticorum Binary System SDSS J0926+3624: Effects of Irradiation onto the Donor Star" , ApJ: 739(1), 34, Sept 20, 2011 [SCI] ( ADS | Fulltext )
  40. Cai MJ;Taam RE, "The Equilibrium Structure of Prolate Magnetized Molecular Cores" , ApJ: 709(1), L79-L82, Jan 20, 2010 [SCI] ( ADS | Fulltext )
  41. Deloye CJ; Taam RE, "Adiabatic Mass Loss and the Outcome of the Common Envelope Phase of Binary Evolution" , ApJ: 719(1), L28-L31, Aug 10, 2010 [SCI] ( ADS | Fulltext )
  42. Hui CY; Cheng KS; Taam RE, "Dynamical Formation of Millisecond Pulsars in Globular Clusters" , ApJ: 714(2), 1149-1154, May 10, 2010 [SCI] ( ADS | Fulltext )
  43. Pan K-C; Ricker PM; Taam RE, "Impact of Type Ia Supernova Ejecta on a Helium-Star Binary Companion" , ApJ: 715(1), 78-85, May, 2010 [SCI] ( ADS | Fulltext )
  44. Politano M; van der Sluys M; Taam RE; Willems B, "Population Synthesis of Common Envelope Mergers. I. Giant Stars with Stellar or Substellar Companions" , ApJ: 720(2), 1752-1766, Sept 10, 2010 [SCI] ( ADS | Fulltext )
  45. Saha K; Tseng YH; Taam RE, "The Effect of Bars and Transient Spirals on the Vertical Heating in Disk Galaxies" , ApJ: 721(2), 1878-1890, Oct 1, 2010 [SCI] ( ADS | Fulltext )
  46. Takata J; Cheng KS; Taam RE, "On the Transition from Accretion Powered to Rotation Powered Millisecond Pulsars" , ApJ: 723(1), L68-L72, Nov 1, 2010 [SCI] ( ADS | Fulltext )
  47. Tam PHT; Hui CY; Huang RHH; Kong AKH; Takata J; Lin LCC; Yang YJ; Cheng KS; Taam RE, "Evidence for Gamma-Ray Emission from the Low Mass X-ray Binary System FIRST J102347.6+003841" , ApJ: 724(2), L207-L211, Dec 1, 2010 [SCI] ( ADS | Fulltext )
  48. Heinke CO; ...; Taam RE; et al., "Further Constraints on Thermal Quiescent X-Ray Emission from SAX J1808.4.3658" , ApJ: 691(2), 1035-1041, Feb 1, 2009 [SCI] ( ADS | Fulltext )
  49. Liu BF; Taam RE, "Application of the Disk Evaporation Model to AGNs" , ApJ: 707(1), 233-242, Dec 10, 2009 [SCI] ( ADS | Fulltext )
  50. Takata J; Taam RE, "Probing the Pulsar Wind in the gamma-ray Binary System PSR B1259-63/SS 2883" , ApJ: 702(1), 100-113, Sep 1, 2009 [SCI] ( ADS | Fulltext )
  51. Belczynski K; Taam RE, "The most massive progenitors of neutron stars: CXO J164710.2-455216" , ApJ: 685(1), 400-405, September 20, 2008 [SCI] ( ADS | Fulltext )
  52. Belczynski K; Taam RE; Rantsioiu E; van der Sluys M, "Black Hole Spin Evolution: Implications for Short-Hard Gamma-Ray Bursts and Gravitational Wave Detection" , ApJ: 682(1), 474-486, July 20, 2008 [SCI] ( ADS | Fulltext )
  53. Deloye CJ; Heinke CO; Taam RE; Jonker PG, "Optical Observations of SAX 1808.4-3658 During Quiescence" , MNRAS: 391(4), 1619-1628, Dec, 2008 [SCI] ( ADS | Fulltext )
  54. Politano M; Taam RE; van der Sluys M; Willems B, "Common Envelope Mergers: A Possible Channel for Forming Single SdB Stars" , ApJ: 687(2), L99-L102, Nov 10, 2008 [SCI] ( ADS | Fulltext )
  55. Taam RE; Liu BF; Meyer F; Meyer-Hofmeister E, "On the Properties of Inner Cool Disks in the Hard State of Black Hole X-Ray Transient Systems" , ApJ: 688(1), 527-536, Nov 20, 2008 [SCI] ( ADS | Fulltext )
  56. Dubus G; Taam RE; Hull C; Watson DM; Mauerhan JC, "Spitzer Space Telescope Observations of the Magnetic Cataclysmic Variable AE Aquarii" , ApJ: 663(1), 516-521, July 1, 2007 [SCI] ( ADS | Fulltext )
  57. Liu BF; Taam RE; Meyer-Hofmeister E; Meyer F, "The Existence of Inner Cool Disks in the Low/Hard State of Accreting Black Holes" , ApJ: 671(1), 695-705, Dec 10, 2007 [SCI] ( ADS | Fulltext )
  58. Willems B; Taam RE; Kolb U; Dubus G; Sandquist EL, "Theoretical orbital period distributions of cataclysmic variables above the period gap: Effects of circumbinary disks" , ApJ: 657(1), 465-481, Mar 1, 2007 [SCI] ( ADS | Fulltext )
  59. Yuan F; Taam RE; Misra R; Wu XB; Xue YQ, "Accretion disk spectra of the brightest ultraluminous X-ray source in M82" , ApJ: 658(1), 282-287, Mar 20, 2007 [SCI] ( ADS | Fulltext )
  60. Becker W; Kramer M; Jessner A; Taam RE; et al., "A multiwavelength study of the pulsar PSR B1929+10 and its X-ray trail" , ApJ: 645(2), 1421-1435, Jul 10, 2006 [SCI] ( ADS | Fulltext )
  61. Cheng KS; Taam RE; Wang W, "Pulsar Wind Nebulae and the Nonthermal X-Ray Emission of Millisecond Pulsars" , ApJ: 641(1), 427-437, Apr 10, 2006 [SCI] ( ADS | Fulltext )
  62. Yuan F; Taam RE; Xue YQ; et al., "Hot one-temperature accretion flows revisited" , ApJ: 636(1), 46-55, Jan 1, 2006 [SCI] ( ADS | Fulltext )
Page Top
TEL: 886-2-3365-2200 FAX: 886-2-2367-7849
General: asiaa_replace2@_asiaa.sinica.edu.tw Media Request: epo_replace2@_asiaa.sinica.edu.tw
11F of AS/NTU Astronomy-Mathematics Building, No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan, R.O.C.