Review on Intrinsic Shape of Elliptical Galaxies

Arun Kumar      Singh; Mukta      Tripathi

Abstract

Elliptical galaxies, as one of the fundamental types of galaxies, have attracted astronomers due to their intriguing properties. In this review, we explore the intrinsic shape of elliptical galaxies, a field that plays a pivotal role in understanding their formation, evolution, and interactions within the cosmos. Methods for intrinsic shape determination using photometric and kinematic methods are extensively discussed. The use of photometric data and surface brightness profiles to derive the intrinsic shapes of elliptical galaxies is examined and triaxial models are reviewed. Constraining the intrinsic shapes of elliptical galaxies is crucial to understanding their formation histories. Elliptical galaxies are characterized by their ellipsoidal, rather than disk-like, shapes, and understanding the underlying factors and their intrinsic shapes of elliptical galaxies determination provides valuable insights into their formation, evolution, and the broader context of galaxy morphology. One key aspect of studying the intrinsic shape of elliptical galaxies involves the analysis of their axial ratios, which describe the flattening of the galaxy along different axes. The axial ratio is defined as the ratio of the semi-minor axis to the semi-major axis of the ellipse representing the galaxy's cross-section. The intrinsic shape can vary from nearly spherical (axial ratio close to 1) to highly elongated (axial ratio significantly different from 1).

Keywords: Intrinsic, elliptical, galaxies, photometric and kinematic, formation and evolution, models, triaxial and distribution.

[1]
Singh, A.K. Distribution of the intrinsic shapes of elliptical galaxies. AIP Conf. Proc.,  2009, 1150, 241-244.

[2]
Singh, A.K. Intrinsic shapes of elliptical galaxies: NGC 5638 and NGC 5813 using modified prior. Int. J. Sci. Res. Technol.,  2015, 1(1), 51-58.

[3]
Singh, A.K. Intrinsic shapes determination of the flat elliptical galaxies using modified prior, International Journal of Management. Technology And Engineering,  2019, IX(III), 1161-1168.

[4]
Singh, A.K. Intrinsic shapes of elliptical galaxies NGC 4374 using modified prior by photometry. Int. J. Emerg. Technol. Adv. Eng.,  2019, IX(X), 345-349. [IJETAE]

[5]
Singh, Arun Kumar Study of intrinsic parameters of elliptical galaxy NGC 1600. Int. J. Sci. Eng. Res.,  2020, 11(12), 214-219.

[6]
Singh, Arun Kumar Two and three dimensional shape distribution of elliptical galaxy NGC 315 using photometry. IJIRT,  2021, 8(6), 432-435.

[7]
Singh, Arun Kumar Determination of intrinsic shape of elliptical galaxy: NGC 32768 using modified prior. Int. Eng. J. Res. Dev.,  2021, 6(6), 1-5.

[8]
Bak, J.; Statler, T.S. The intrinsic shape distribution of a sample of elliptical galaxies. Astron. J.,  2000, 120(1), 110-122. [AJ]
 [http://dx.doi.org/10.1086/301437]

[9]
Barbara, S. Ryden, the shapes of elliptical galaxies with central density cusps and massive dark objects. Astrophys. J.,  1998, 1, 1-27.

[10]
Binney, J. The intrinsic shapes of elliptical galaxies. Mon. Not. R. Astron. Soc.,  1995, 212(3), 767-784.

[11]
Chakraborty, D. K. Ellipsoidal mass models with varying axial ratios. A&A, 2004, 423-501.

[12]
Chakraborty, D.K.; Singh, A.K.; Gaffar, F. Variation in the intrinsic shapes of elliptical galaxies. Mon. Not. R. Astron. Soc.,  2008, 383(4), 1477-1484.
 [http://dx.doi.org/10.1111/j.1365-2966.2007.12646.x]

[13]
Chakraborty, D.K.; Diwakar, A.K.; Pandey, S.K. Intrinsic shapes of very flat elliptical galaxies. Mon. Not. R. Astron. Soc.,  2011, 412(1), 585-590.
 [http://dx.doi.org/10.1111/j.1365-2966.2010.17930.x]

[14]
Statler, T.S. Uncovering the intrinsic shapes of elliptical galaxies, 3: Practical modeling. Astrophys. J.,  1994, 425, 500.

[15]
Tenjes, P.; Busarello, G.; Lango, G.; Zaggia, S. On the intrinsic shape of elliptical galaxies. A&A, 1993, 275-61.

[16]
Stark, A.A. Triaxial models of the bulge of M31. Astrophys. J.,  1977, 213, 368.
 [http://dx.doi.org/10.1086/155164]

[17]
Gadotti, D.A. Structural properties of pseudo-bulges, classical bulges and elliptical galaxies: A sloan digital sky survey perspective. Mon. Not. R. Astron. Soc.,  2009, 393(4), 1531-1552.
 [http://dx.doi.org/10.1111/j.1365-2966.2008.14257.x]

[18]
Binggeli, B. On the intrinsic shape of elliptical galaxies. Astron. Astrophys.,  1980, 82(3), 289-294.

[19]
Benacchio, L.; Galletta, G. Triaxiality in elliptical galaxies. Mon. Not. R. Astron. Soc.,  1980, 193(4), 885-894.
 [http://dx.doi.org/10.1093/mnras/193.4.885]

[20]
Binney, J.; de Vaucouleurs, G. The apparent and true ellipticities of galaxies of different hubble types in the second reference catalogue. Mon. Not. R. Astron. Soc.,  1981, 194(3), 679-691.
 [http://dx.doi.org/10.1093/mnras/194.3.679]

[21]
Franx, M.; Illingworth, G.; de Zeeuw, T. The ordered nature of elliptical galaxies - Implications for their intrinsic angular momenta and shapes. Astrophys. J.,  1991, 383, 112.
 [http://dx.doi.org/10.1086/170769]

[22]
Statler, T.S.; Fry, A.M. Uncovering the intrinsic shapes of elliptical galaxies. 2: Approximate kinematic shape indicators. Astrophys. J.,  1994, 425, 481.
 [http://dx.doi.org/10.1086/174002]

[23]
Binney, J. Is the flattening of elliptical galaxies necessarily due to rotation? Mon. Not. R. Astron. Soc.,  1976, 177(1), 19-29.
 [http://dx.doi.org/10.1093/mnras/177.1.19]

[24]
Davis, M.H. Measuring individual differences in empathy: Evidence for a multidimensional approach. J. Pers. Soc. Psychol.,  1983, 44(1), 113-126.
 [http://dx.doi.org/10.1037/0022-3514.44.1.113]

[25]
Vincent, R.A.; Ryden, B.S. The dependence of galaxy shape on luminosity and surface brightness profile. Astrophys. J.,  2005, 623(1), 137-147.
 [http://dx.doi.org/10.1086/428765]

[26]
Binney, J.; Merrifield, M.; Astronomy, G. Galactic Astronomy; Princeton University Press: Princeton, NJ,  1998, QB857.B522.

[27]
Méndez-Abreu, J. Structural properties of disk galaxies. I. The intrinsic equatorial ellipticity of bulges. A&A, 2008, 478(2), 353-:369.

[28]
Hubble, E. The Realm of the Nebulae; Yale University Press, 1926. 

[29]
Hussein, M.M.; Saafan, S.A.; Abosheiasha, H.F.; Zhou, D.; Tishkevich, D.I.; Abmiotka, N.V.; Trukhanova, E.L.; Trukhanov, A.V.; Trukhanov, S.V.; Hossain, M.K.; Darwish, M.A. Preparation, structural, magnetic, and AC electrical properties of synthesized CoFe2O4 nanoparticles and its PVDF composites. Mater. Chem. Phys.,  2024, 317, 129041.
 [http://dx.doi.org/10.1016/j.matchemphys.2024.129041]

[30]
Migas, D.B.; Turchenko, V.A.; Rutkauskas, A.V.; Trukhanov, S.V.; Zubar, T.I.; Tishkevich, D.I.; Trukhanov, A.V.; Skorodumova, N.V. Temperature induced structural and polarization features
  in BaFe 12 O 19. J. Mater. Chem. C Mater. Opt. Electron. Devices, 2023, 11(36), 12406-12414-12406-12414.
 [http://dx.doi.org/10.1039/D3TC01533E]

[31]
Holmberg, E. A study of the spiral nebulae NGC 4102 and 4559. Annals of Harvard College Observatory,  1940, 105, 1-22.

[32]
De Vaucouleurs, G. Classification and morphology of external galaxies. Handb. Phys.,  1959, 11, 275-310.
 [http://dx.doi.org/10.1007/978-3-642-45932-0_7]

[33]
Tully, R.B.; Fisher, J.R. A new method of determining distances to galaxies. Astron. Astrophys.,  1977, 54(3), 661-673.

[34]
Binney, J. Testing for triaxiality with kinematic data. Mon. Not. R. Astron. Soc.,  1985, 212(4), 767-781.
 [http://dx.doi.org/10.1093/mnras/212.4.767]

[35]
Bertola, F.; Capaccioli, M. Internal kinematics of elliptical galaxies. Astrophys. J.,  1975, 200, 439-448.
 [http://dx.doi.org/10.1086/153808]

[36]
Tonry, J.; Schneider, D. Irregularities in the redshift distribution of distant galaxies. Astrophys. J.,  1988, 328, 500-506.

[37]
Dressler, A.; Lynden-Bell, D.; Burstein, D.; Davies, R.L.; Faber, S.M.; Terlevich, R.; Wegner, G. Spectroscopy and photometry of elliptical galaxies. I - A new distance estimator. Astrophys. J.,  1987, 313, 42-58.
 [http://dx.doi.org/10.1086/164947]

[38]
Djorgovski, S.; Davis, M. Fundamental properties of elliptical galaxies. Astrophys. J.,  1987, 313, 59-70.
 [http://dx.doi.org/10.1086/164948]

[39]
Van der Marel, R.P. The dynamics of globular clusters in the core of M87. Astrophys. J.,  1990, 352, 77-87.

[40]
Dehnen, W. A family of potential-density pairs for spherical galaxies and bulges. Mon. Not. R. Astron. Soc.,  1993, 265(1), 250-256.

[41]
de Zeeuw, P.T.; Carollo, C.M. A family of triaxial mass models with central cusps. Mon. Not. R. Astron. Soc.,  1996, 281(4), 1333-1340.
 [http://dx.doi.org/10.1093/mnras/281.4.1333]

[42]
Faber, S.M.; Tremaine, S.; Ajhar, E.A.; Byun, Y.I.; Dressler, A.; Gebhardt, K.; Grillmair, C.; Kormendy, J.; Lauer, T.R.; Richstone, D. The centers of early-type galaxies with HST. IV. Central parameter relations. Astron. J.,  1997, 114, 1771.
 [http://dx.doi.org/10.1086/118606]

[43]
Gerald, D. The dynamical evolution of massive black hole binaries — II. Self-consistent N-body integrations. Mon. Not. R. Astron. Soc.,  1997, 2(6), 533-554.

[44]
Magorrian, J.; Tremaine, S.; Richstone, D.; Bender, R.; Bower, G.; Dressler, A.; Faber, S.M.; Gebhardt, K.; Green, R.; Grillmair, C.; Kormendy, J.; Lauer, T. The demography of massive dark objects in galaxy centers. Astron. J.,  1998, 115(6), 2285-2305.
 [http://dx.doi.org/10.1086/300353]

[45]
Merritt, D. Intrinsic shapes of elliptical galaxies. Astrophys. J.,  2009, 694(2), 959-974.
 [http://dx.doi.org/10.1088/0004-637X/694/2/959]

[46]
van den Bosch, R.C.E.; van de Ven, G. Recovering the intrinsic shape of early-type galaxies. Mon. Not. R. Astron. Soc.,  2009, 398(3), 1117-1128.
 [http://dx.doi.org/10.1111/j.1365-2966.2009.15177.x]

[47]
Singh, A.K. Study of the intrinsic parameters of some mass models of elliptical galaxies. ASI Conf. Ser.,  2011, 3, pp. 91-94.

[48]
Rodríguez, Silvio The intrinsic shape of galaxies in SDSS/Galaxy Zoo. Mon. Not. R. Astron. Soc.,  2013, 434(3), 2153-2166.
 [http://dx.doi.org/10.1093/mnras/stt1168]

[49]
Jacob, D. The massive survey. XVII. A triaxial orbit-based determination of the black hole mass and intrinsic shape of elliptical galaxy NGC 2693. Astrophys. J.,  2022, 928, 178.
 [http://dx.doi.org/10.3847/1538-4357/ac58fd]

[50]
Fasano,G.Fresh views of elliptical galaxies. ASP Conf. Ser.,  1995, 37.

[51]
Thakur, P.; Chakraborty, D.K. Correlated projected properties of some triaxial mass models: Implications for their intrinsic shapes. Mon. Not. R. Astron. Soc.,  2001, 328(1), 330-338.
 [http://dx.doi.org/10.1046/j.1365-8711.2001.04794.x]

[52]
Schwarzschild, M. A numerical model for stationary triaxial stellar systems. Astrophys. J.,  1979, 232, 236-247.
 [http://dx.doi.org/10.1086/157282]

[53]
 Modern galaxy composition. Available from:. https://www.freepik.com/free-vector/modern-galaxy-composition_3345429.htm#fromView=search&page=2&position=7&uuid=0322b900-02c7-4f94-9b78-1cb7dd52ad14

[54]
Aesthetic galaxy element vector set. Available from:. https://www.freepik.com/free-vector/aesthetic-galaxy-element-vector-set_17221408.htm#fromView=search&page=1&position=14&uuid=9093b085-dd88-4eb1-a648-6fd5ecefa3f3

Cite As

Current Physics

Review on Intrinsic Shape of Elliptical Galaxies

Abstract