Binil Aryal Central Department of Physics Tribhuvan University, Kirtipur

Size: px

Start display at page:

Download "Binil Aryal Central Department of Physics Tribhuvan University, Kirtipur"

Cody Fowler
5 years ago
Views:

1 Binil Aryal Central Department of Physics Tribhuvan University, Kirtipur

2 Outline >> A&A Education in Nepal >> A&A Research in Nepal >> Our difficulties/limitations >> Future Scopes >> Summary

3 2007: Tribhuvan University has offered Astrophysics course at M.Sc. (Physics) Level >> contains stellar astrophysics, origin of elements, galactic dynamics & computational stuff >> recently introduced a multidiciplinary course (Astronomy & Space Science) to undergraduate students Government of Nepal established a high level committee to study the R&D activities in Astronomy >> 16 inch Schmidt telescope (Nagarkot) No other University has offered A&A course till date

4 2006: begun M.Sc. Dissertation in Astrophysics >> Spatial orientation of Galaxies in the cluster (2006-till date) 2007: later expanded area of research >> ISM interactions(2007-till date] >> Chiral Symmetry in LSS (2007-till date) >> Cosmological Constant (2008-till date) >> Photodissociation region (2010-till date) >> Search of AGN in X-ray clusters (2012-till date) Till date: >> 72 students have completed their masters thesis in A&A >> Three Ph.D. projects are running >> 16 (4+12) graduates are doing masters dissertation

5 Past thesis students ( ) 1. Dr. Sunil Mani Kandel (2007 / USA) 2. Dr. Ajya Mishra (2007 / USA) 3. Dr. P. Lammichhane (2008 / USA) 4. Dr. Nirmal J. Ghimire (2008 / USA) 5. Dr. Sanjaya Paudel (2008 / Germany) 6. Mr. K. Simkhada (2008 / USA) 7. Mr. Ashok Devkota (2009 / USA) 8. Mr. Tulsi Gyawali (2009 / USA) 9. Mr. Barun K. Gupta (2009 / USA) 10. Mr. Tara Nidhi Acharya (2009 / USA) 11. Mr. Prajwal Kafle (2010 / Australia) 12. Mr. Prakash Thapa (2010 / USA) 13. Mr. Nauraj Pokhrel (2010 / USA) 14. Mr. Binod Rai (2010 / USA) 15. Mr. Lekhnath Paudel (2010 / USA) 16. Mr. Disoj Nupane (2010 / USA) 17. Mr. Hari Sharma (2010 / Italy) 18. Mr. Udhhav Chamlagain (2010 /France) 19. Mr. Sunil Karn (2010 / USA) 20. Mr. Bhim Chamlagain (2011 / USA) 21. Mr. Rajesh Panthi (2011 / USA) 22. Mr. Rajesh K Bachchan (2011 / Sweden) 23. Mr. Chinta Mani Aryal (2012 / USA) 24. Mr. Raj Kiran Koju (2012 / USA) 25. Mr. Amrit Ladauri (2012 / USA) 26. Mr. Riwaj Pokhrel (2012 / USA) 27. Mr. Utsab Shrestha (2012 / USA) 28. Mr. Binod Adhikari (2012 / Brazil) 29. Mr. Tak Pd. Adhikari (2013 /Poland) 30. Mr. Rishi Ram Paudel (2012 / USA) 31. Mr. Ramesh Mainali (2013 / USA) 32. Mr. Suman K. Paudel (2013 / USA) 33. Mr. Sudeep Neupane (2013 / Chile) 34. Mr. Taiendra Neupane (2013 / USA) 35. Mr. Anil Aryal (2013 / USA) 36. Mr. Amrit Kafle (2013 / USA) 37. Mr. Balram Kaderiya (2013 / USA) 38. Mr. Sagar paudel (2013 / USA) They are ambassador of A&A alumni of Nepal. They are in touch in several ways: software, collaborative works, etc

6 PUBLICATIONS (Peer Reviewed International Journal) 1. B. Aryal, H. Bhattarai, S. Dhakal, C. Rajbahak & W. Saurer, Spatial orientation of galaxies in 6 rotating clusters, MNRAS,., (2013) 2. B. Aryal, S.N. Yadav & W. Saurer, Spatial orientation of galaxies in the Zone of Avoidance, Bulletin of Astron. Astron. Soc. Ind. (BASI), 40, 65 (2012) 3. B. Aryal, R. R. Paudel, W. Saurer, Spatial orientation of angular momentum vector of galaxies in three merging binary clusters, Astrophysics & Space Science Journ. (Springer), 337, 313 (2012) 4. B. Aryal, Winding Sense of Galaxies Around the Local Supercluster, Research in Astronomy & Astrophysics Journ., 11, 293 (2011) 5. B. Aryal, R. K. Bachchan & Saurer W., Optical Search Limit and Preferred Position Angle Distribution of Galaxies in 35 Clusters, Bulletin of Astron. Astron. Soc. Ind. (BASI), 38, 165 (2010) 6. B. Aryal, C. Rajbahak & R. Weinberger, A giant dusty bipolar structure around the planetary nebula NGC 1514, Monthly Notice of Royal Astronomical Society (MNRAS), 402, 2, 1307 (2010) 7. B. Aryal, C. Rajbahak & R. Weinberger, Planetary Nebula NGC 6826 and NGC 2988: early aspherical mass loss?, Astrophysics & Space Science Journ. (Springer), 323, 323 (2009) 8. B. Aryal, P. Kafle & W. Saurer, Radial velocity dependence in the spatial orientations of galaxies in and around the local supercluster, Monthly Notice of Royal Astronomical Society (MNRAS), 389, 741 (2008) 9. B. Aryal, D. Nupane & W. Saurer, Morphological dependence in the spatial orientations of galaxies around the Local Supercluster, Astrophysics & Space Science Journ. (Springer), 314, 177 (2008) 10. B. Aryal, S. Paudel & W. Saurer, Coexistence of chiral symmetry restoration and random orientation of galaxies, Astrophysics & Astronomy Journ. (A&A), 479, 397 (2008) 11. B. Aryal, S. Paudel & W. Saurer, Spatial Orientation of galaxies in 7 clusters of BM type II, Monthly Notice of Royal Astronomical Society (MNRAS), 379, 1011 (2007) 12. B. Aryal, S. R. Acharya & W. Saurer, Chirality of spiral galaxies in the Local Supercluster, Astrophysics & Space Science Journ. (Springer), 307, 369 (2007) 13. B. Aryal, S. M. Kandel & W. Saurer, Spatial orientation of galaxies in the core of the Shapley Concentration: The cluster Abell 3558, Astrophysics & Astronomy Journ. (A&A), 458, 377 (2006) 14. B. Aryal & R. Weinberger, A new high latitude cone like far-ir nebula, Astrophysics & Astronomy Journ. (A&A), 446, 213 (2006) 15. B. Aryal & W. Saurer, Spin vector orientation of galaxies in ten clusters of BM type II-III, Monthly Notice of Royal Astronomical Society (MNRAS), 366, 438 (2006) 16. B. Aryal & W. Saurer, Spin vector orientation of galaxies in the region 19h26 m00s<ra(2000)<20h$19m00s, -68 o <Dec.(2000)<-65 o, Monthly Notice of Royal Astronomical Society (MNRAS), 360, 125 (2005) 17. B. Aryal & W. Saurer, Spin vector orientation of galaxies in seven Abell clusters of BM type III, Astrophysics & Astronomy Journ. (A&A), 432, 841 (2005) 18. B. Aryal & W. Saurer, Morphological dependence in the spatial orientation of Local Supercluster galaxies, Astrophysics & Astronomy Journ. (A&A), 432, 431 (2005) 19. R. Weinberger & B. Aryal, Huge Dust Structures and Cavities Around PNe: NGC 6826 and NGC 2899, Edited by Margaret Meixner, Joel H. Kastner, Bruce Balick and Noam Soker, ASP Conf. Proc., Vol San Francisco: Astronomical Society of the Pacific, 2004., p (2004) 20. R. Weinberger & B. Aryal, Asymmetric mass-loss on the AGB: examples from IRAS data, Edited by Y. Nakada, M. Honma and M. Seki. Astrophysics and Space Science Library, Vol. 283, Dordrecht: Kluwer Academic Publishers, ISBN , p (2003) 21. B. Aryal & W. Saurer, Spin vector orientation of galaxies in seven Abell clusters of BM type I, A&A, 425, 871 (2004) 22. B. Aryal & R. Weinberger: Structure of Interstellar Bubbles: A Numerical Time-Dependent Calculation, Supplementary Issue 2, Vol. 324, Short Contributions of the Annual Scientific Meeting of the Astronomische Gesellschaft in Berlin, September 23-28, 7 (2002) 23. B. Aryal & W. Saurer, The influence of selection effects on the isotropic distribution curve in galaxy orientation studies, Edited by José G. Funes, S. J. and Enrico Maria Corsini. San Francisco: Astronomical Society of the Pacific. ISBN: , ASP Conf. Ser., Vol. 230, p (2001) 24. B. Aryal & W. Saurer, Comments on the expected isotropic distribution curve in galaxy orientation study, A&AL, 364, L97-L100 (2000)

7 Collaborators Innsbruck University, Austria Prof. Ronald Weinberger, Prof. Walter Saurer University of Washington, Seattle, USA Prof. Noam Soaker, Prof. Bruce Ballik KISO Observatory, Japan Prof. J. Okamura, Prof. Y. Kashikawa Napoli University, Italy Prof. A. Lattanzi Krakow Observatory, Poland Prof. W. Godlowski Koeln University, Germany Prof. J. Stutzki SN Bose, Calcutta, India Prof. S. N. Chakraborty

8 No telescope / no separate department for A&A / we use the available huge database, define science / mostly collaborative in nature / no funding from internal sources / got ASF, ESF, IAU mini projects / few are in pipeline DATA POSS II: Sanjaya Paudel ESO 2: Sanjaya, Dirgha Shahi, etc DSS2: Shiv Raj Acharya, Pramod Lammichhane, etc NANTEN: Riwaj Pokhrel & Balram Kaderia IRAS: Ishwor Paudel and many more COBE: Ajay Mishra, Nirmal Ghimire WMAP: C. Rajbahak, Rajesh K Bachchan SPITZER: Krishna Simkhada SDSS: Biplav Acharya and many more 2DFGRS: Saroj D.C. RXTE & BAT: Suresh Bhattarai XMM NEWTON: Padam & Ramesh Mainali

9 The spatial orientation of spin vectors of galaxies can be an indicator of the initial conditions when galaxies and clusters formed, provided the angular momenta of galaxies have not been altered too much since their formation.

# Primordial Vorticity PANCAKE MODEL (Doroshkev and Shandarin, 1978) # SV parallel # Clusters were first formed and they fragmented into galaxies.

10 Li (1998) : Global rotation of the Universe TURBULENCE MODEL (Ozernoy 1978) # SV perpendicular # First flattened, rotating protoclusters were formed due to cosmic vorticity in the early universe. # Primordial Vorticity PANCAKE MODEL (Doroshkev and Shandarin, 1978) # SV parallel # Clusters were first formed and they fragmented into galaxies. # Adiabatic fluctuations HIERARCHY MODEL (Peebles 1969) # SV random # Galaxies were first cenarioformed and then obtained their angular momenta by tidal forces while they were gathering gravitationally to form a cluster with no dessipation

Measured parameters α, δ, p and b/a photometric axial ratio (Forque & Pautral, 1986) Physical Reference System (Godlowski 1986) inclination angle (Giovanni et al.

11 Measured parameters α, δ, p and b/a photometric axial ratio (Forque & Pautral, 1986) Physical Reference System (Godlowski 1986) inclination angle (Giovanni et al. 2001) removel of selection effects (Aryal & Saurer 2006) polar & azimuthal angle (θ & φ) GOBAD1.0 Aryal et al. MNRAS (2013) (SkyView, SIMBAD, NED, etc) -Fourier test -K-S test -Kuiper test -Chi Square Test -Auto-correlation test

12 3-D approach sin θ = - cos i sin B ± sin i sin P cos B sin φ = (cos θ)-1 [- cos i cos B sin L + sin (± sin P sin B sin L ± cos P cos L) (Flin & Godlowski, 1986) PA-inclination method (Flin & Godlowski 1986, Godlowski 1993, 1994, Aryal & Saurer 2000, Flin 2001, Baier et al. 2003, Aryal & Saurer 2004, 2005a & 2005b) axial ratios, PAs & positions polar & azimuthal angle

past works FG (1986, MNRAS 222) : 1275 galaxies KO (1992, PASJ 44) : 618 northern bright spirals G (1993, MNRAS 265) : 2227 galaxies G (1994, MNRAS 271) : 2227 galaxies HWSL (1995, A & A 302) : 310

13 past works FG (1986, MNRAS 222) : 1275 galaxies KO (1992, PASJ 44) : 618 northern bright spirals G (1993, MNRAS 265) : 2227 galaxies G (1994, MNRAS 271) : 2227 galaxies HWSL (1995, A & A 302) : 310 galaxies / Virgo / S & S0 WHSL (1997, A & A 323) : 128 galaxies / Coma / S & S0 YHSH (1997, ApJ 495) : 302 field galaxies / PANBG / S & S0 HYSWL (1998, AJ 114) : 220 bright isolated field galaxies GBM (1998, A & A 339) : 491 galaxies : A754 / PA analysis GO (1999, MNRAS 303) : subclusters of LSC Flin P. (2001, MNRAS) : Coma cluster In order to minimize the selection effects due to positions and inclination angles we have done numerical simulations. The true spatial distribution of the SVs of galaxies we have assumed to be isotropical. Our results are based on calculations including 10 6 virtual galaxies.

14 Aryal & Saurer 2001 number (arbitrary scale) number (arbitrary scale) a high B b/a < < b/a < < b/a < < b/a < 0.90 cosine a L:0 o -30 o L:180 o -210 o θ (deg) B & i : no selection L:30 o -60 o L:60 o -90 o L:210 o -240 o L:240 o -270 o L:270 o -300 o L:120 o -150 o L:90 o -120 o L:300 o -330 o L:330 o -360 o L:150 o -180 o φ (deg) The isotropic polar angle distribution is independent of positions only when there is no selections on i. b high B b/a < 0.30 b/a < 0.50 b/a < 0.70 b/a < 0.90 cosine b L:60 o -90 o θ (deg) b/a < 0.30 b/a < 0.50 b/a < 0.70 b/a < 0.90 b/a : no selection φ (deg) The polar angle distribution is different for face-on and edge-on galaxies when making selections on B. c low B b/a < < b/a < < b/a < < b/a < 0.90 cosine c θ (deg) b/a < < b/a < < b/a < < b/a < 0.90 b/a : no selection L : 60 o -90 o φ (deg) The azimuthal angle distribution remains unchanged for face-on and edge-on galaxies when the range of L is full. d low B b/a < 0.30 b/a < 0.50 b/a < 0.70 b/a < 0.90 cosine θθ distribution (deg) distribution is b/a < 0.30 independent of L 0.40 < b/a < 0.50 but changes 0.60 < b/a with < 0.70 B 0.80 < b/a < 0.90 when making b/a : no selection selections on i. d L : 0 o -30 o θ distribution is independent of i if there are no selections on positions. φ distribution changes with L even when the range of i & B is φ (deg) full The isotropic azimuthal angle distribution is independent of B provided the range of i & L is full.

15 number Hu et al. (1995) We noticed that the selection effects concerning positions and inclination of galaxies can remarkably change the shape of the expected isotropic distributions isotropic curve Hu et al. (1998) θ (deg) 40 (Aryal & Saurer, 2008) number φ (deg) isotropic curve

16 δ(2000) A0168 A0401 A0042 A2721 A0426 A3128 A2256 A0787 A1412 A1920 A2255 A1767 A1904 A2197 A1227 A2061 A2199 A1035 A2089 A2065 A1775 A2142 A1367 A2151 A1020 A1809 A2048 A3556 A3562 A3558 A3560 A3627 A2554 A A h 00 m 04 h 00 m 08 h 00 m 12 h 00 m 16 h 00 m 20 h 00 m 24 h 00 m α(2000) > 200,000 galaxies (SDSS, 2dFGRS, POSS II, ESO,...) 2 Superclusters, Clusters of all BM types (12 Rotating / 3 MB clusters)

17 80 60 A3558 total P (χ 2 ) = 75% P( 1 ) = 99% Results number polar angle (deg) C/σ(C) = /σ( 11 ) = Aryal et al., 2013, submitted

18 100 A3558 total P (χ 2 ) = 44% P( 1 ) = 57.5% 80 number azimuthal angle (deg) C/σ(C) = /σ( 11 ) = + 1.1

19 A3558 Incoherent cluster-group merging: Bardelli et al. (1998) Cluster-cluster collision: Matcalfe et al. (1994) RXTE 8-20 kev 249 galaxies P (χ 2 ) = 0.01% P( 1 ) = 2.42% C/σ(C) = /σ( 11 ) = -2.7

20 number A θ (deg) number a θ (deg) A2151 number a θ (deg) A2781 Aryal & Saurer, Ap&SS, 2009 Aryal et al., MNRAS, 2009) Aryal & Saurer, MNRAS, 2011 number 50 A φ (deg) θ : anisotropy φ : isotropy b number 60 A b φ (deg) θ : isotropy φ : isotropy number b A φ (deg) θ : anisotropy φ : anisotropy

polar angle (θ) azimuthal angle (φ) AC isotropy anisotropy isotropy anisotropy ll 1 1 bimodal ll 2 2 bimodal A0042 - - - - - - A0168 - - - - - - A0401 - - - - - - A0426 - - - - - - A0787 - - - - - -

21 polar angle (θ) azimuthal angle (φ) AC isotropy anisotropy isotropy anisotropy ll 1 1 bimodal ll 2 2 bimodal A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A polar angle 21: ll 2 : 7 : bimodal B. Aryal, P. Kafle & W. Saurer, MNRAS, 389, 741 (2008) B. Aryal, D. Nupane & W. Saurer, Ap&SS, 314, 177 (2008) B. Aryal, S. Paudel & W. Saurer, MNRAS, 379, 1011 (2007) B. Aryal, S. M. Kandel & W. Saurer, A&A, 458, 377 (2006) B. Aryal & W. Saurer, MNRAS, 366, 438 (2006) B. Aryal & W. Saurer, MNRAS, 360, 125 (2005) B. Aryal & W. Saurer, A&A, 432, (2005) B. Aryal & W. Saurer, A&A, 432, (2005) B. Aryal & W. Saurer, A&A, 425, p (2004) azimuthal angle 6: ll 20 : 3 : bimodal

22 We noticed a systematic change in the galaxy alignments from early-type (BM I) to late-type (BM III) clusters. This result suggests that the spiralrich (late-type) clusters (BM II-III and BM III) show a preferred alignment than that of elliptical-rich (early-type) clusters (Aryal, Paudel & Saurer, MNRAS, 2007). The spatial orientation of galaxies in 112 clusters were studied till date (Peebles et al , Godlowski et al ; Flin et al. 2001, Baier et al. 2003, MacGivalli et al. 2004, Aryal et al ). In most cases no preferred alignment is noticed (Hierarchy model). However, few clusters strongly support Pancake model. The alignments of galaxies in the cluster is found to be independent of the mean RV of the cluster. In few clusters (A3560, A3128, A3879, A2089, A1020, A1904, A2255, A1412, A2061, A2065 and the Virgo) we noticed preferred alignments (Aryal & Saurer, MNRAS, 2006).

23 A preferred alignment of SV orientations of galaxies for the rich (R >$ 3) and massive clusters is noticed. We could not notice any significant difference concerning galaxy orientation of face-on and edge-on galaxies (Aryal & Saurer, A&A, 2006). The spin vectors of barred spirals in LSC show a weak preferred alignment. Morphological dependence can be suspected for the late-type SB galaxies. The ellipticals, lenticulars and the irregulars show a random orientation (Aryal & Saurer, A&A, 2006; Aryal, Nuepane & Saurer 2008). A significant morphological dependence is noticed concerning galaxy alignment: SV projections ofgalaxies in early-type cluster tend to be oriented perpendicular with respect to the LSC center whereas the SV projections of galaxies in late-type cluster tend to point towards the LSC center (Aryal, Paudel & Saurer, MNRAS, 2007).

24 We found a weak relation between the preferred inclination angle (i) and the mean RV of the cluster. For distant cluster, he preferred i value is found to be less than that of the nearby cluster. These preferred alignments are found to be independent of the mean RV, distance and richness class of the cluster (Aryal, Nupane & Saurer, Ap&SS, 2008). We found a random alignment of SVs of total galaxies that have RVs < 5,000 km/s with respect to the LSC. The SV projections of these galaxies tend to be oriented tangentially with respect to the Virgo cluster center. Interestingly, Aryal & Saurer (2005) found a similar result when analysing 4,073 LSC galaxies that have RV < 3\,000 km/s with respect to the Supergalactic coordinate system (Aryal, Kafle & Saurer, MNRAS, 2008).

25 2006: begun M.Sc. Dissertation in Astrophysics >> Spatial orientation of Galaxies in the cluster (2006-till date) 2007: later expanded area of research >> ISM interactions(2007-till date] >> ChiralSymmetry in LSS (2007-till date) >> Cosmological Constant (2008-till date) >> Photodissociationregion (2010-till date) >> Search of AGN in X-ray clusters (2012-till date)

26 The fact that galaxies rotate might be a clue as to the physical conditions under which these systems formed. This fact could allow us to obtain knowledge concerning the origin of the angular momenta of galaxies in clusters. [13 publications] Analysis of the galaxy rotation curve shows that the missing galactic dark matter (energy?) can be explained in terms of cosmological constant. [2 publications] Dust structures around PNe & WD might represent fossil remnants of the early spherical mass loss and the subsequent bipolar massloss. [4 publications] The progressive loss of chirality might have some connection with the rotationally supported (spirals, barred spirals) and randomized (lenticulars, ellipticals) systems. Thus, we suspect that the dynamical processes in the cluster evolution give rise to a dynamical loss of chirality. [2 publications]

27 Thanks for your attention

28 An expression for rotational velocity of a test particle around the central mass in the invariant plane is derived. For this, a line element of Schwarzschild de-sitter space-time is used to study the effect of cosmological constant (Λ) on the motion of both massive and massless particles in the Universe. Einstein field eq. Schwarzchild de Sitter space-time circular motion time-like geodesic (Aryal & Khanal 2009) 11/15/2013 Beijing BCSPIN Summer School 28

29 Cosmological constant Particle Physics Quark-Hadron Λ=0 String Theory Λ=0 Quantrum Field Theoy Λ=0 Standard Model Λ=0 Λ General Relativity Λ 0 Cosmology Inflation Λ 0 Supernovae Λ 0 Missing Matter Λ 0 Several branches of physics need a nonzero Cosmological constant in order to explain key physical phenomena, whilst in others a non-zero value presents a fundamental problem Galaxy Roration Curve Λ=? 29

30 studied observed database of rotation curves of different types of spiral galaxies.. (database: Sofue et al. 2001, 2004 & 2010, etc)

31 Above equation is actually for the exterior Schwarzschild - de Sitter space-time. Better results will be obtained if we model the expression for the interior Schwarzschild-de Sitter spacetime (within the galaxy). BCVSPIN 2013, Hongzhou, China 9 June 2013

32 Observed data: Sofue 2008

33 Aryal, Bachchan & Khanal, 2010

Λ ~ (2.213±0.443) x 10-42 km -2 to (9.014±1.803) x 10-39 km -2 b Flattened region: convergence? Blue-shifted Galaxy (NGC0224) logm (x 10 39 kg) 1 0.1 0.01 0.

35 Λ ~ (2.213±0.443) x km -2 to (9.014±1.803) x km -2 b Flattened region: convergence? Blue-shifted Galaxy (NGC0224) logm (x kg) We found positive Λ value (in agreement with type Ia Supernova data) for all 127 S & SB galaxies, suggesting accelerating universe! logλ (x km -2 ) (MNRAS, 2013, in press) Beijing BCSPIN Summer School M ~ (1.574±0.315) x10 7 M to (1.950±0.390) x10 10 M

arxiv: v1 [astro-ph.ga] 9 Jun 2016

arxiv: v1 [astro-ph.ga] 9 Jun 2016 Astrophysics and Space Science manuscript No. (will be inserted by the editor) S. N. Yadav 1, B. Aryal 1 W. Saurer 2 Spatial Orientation of Spin Vectors of Blue-shifted Galaxies arxiv:1606.02881v1 [astro-ph.ga]