臺灣博碩士論文加值系統

我們透過SDSS MaNGA提供的積分場光譜觀測資料，研究16個具恆星形成的早型星系（SFETGs）的性質。本研究中的早型星系均由星系動物園2（Galaxy Zoo 2）提供的星系型態資料篩選後得出，並以各個星系的BPT圖將其細分為具恆星形成的早型星系與不具恆星形成的早型星系（NSFETGs）。這兩類星系的性質差異在於SFETGs的質量較小、顏色較藍，且恆星形成活動旺盛，而NSFETGs則質量較大、顏色偏紅、無恆星形成活動。藉由空間解析的觀測圖我們發現部分的SFETGs其氣體與恆星的旋轉方向角度不一致，推論出供應恆星形成活動的氣體源自於星系外部。從游離氫發射線的等效寬度之空間分布圖的樣貌，我們將SFETGs再細分為圓型、偏移型、雙峰型、多峰型四類。為了了解星系旋轉的比角動量（specific angular momentum），我們採用了λ_R這個參數。這四類SFETGs其氣體的λ_R有所不同，其中圓型、偏移型這兩類的λ_R較小，而雙峰、多峰型則較大。我們發現氣體角動量較少的星系，其恆星形成活動較強烈。此外，為了驗證已知的sSFR-Dn4000關係是否在局域同樣適用，我們採用了局部的Hα等效寬度作為局部sSFR，發現這個反相關不僅適用於廣域，也適用於局域。至於恆星年齡剖面的梯度，對於圓型、偏移型、雙峰型與多峰型四類分別為正向、混和、反－正向及反向，這些梯度反映出不同類型的星系的氣體分布。

We investigate the properties of 16 star-forming early-type galaxies (SFETGs) with
the integral field spectroscopy (IFS) from SDSS MaNGA. The ETGs are selected from
the morphological parameters provided by Galaxy Zoo 2 and then classified into SFETGs and Non-SFETGs (NSFETGs) through the BPT maps. The differences of the galaxy properties between the SFETGs and NSFETGs are that the SFETGs are less massive, showing bluer color, and, of course, more star-forming, while the NSFETGs are massive, red, and passive. The origins of the gas fueling the star formation may be external because of the existence of the kinematically misaligned gas and stars in some SFETGs. We further classify the SFETGs into round, shifted, double-peaked, and multiple-peaked using the morphology derived from the maps of the equivalent width (EW) of the Hα emission line. To express the specific angular momentum of the gas of the galaxies, we employ the λ_R parameter. These four types of morphology correspond to different levels of λ_R of gas; the round and the shifted SFETGs are at the lower levels, whereas the double- and multiple-peaked ones are at the higher ones. Based on the relation between λ_R and local Hα EW, the loss of the angular momentum of gas may enhance the star formation. To verify the well-known sSFR-Dn4000 relation on the local scale, we adopt the Hα EW to be the local sSFR. We find that the anti-correlation works on the local scale as well. The gradients of the stellar age profiles of the round, shifted, double-peaked, and multiple-peaked SFETGs are positive, mixed, negative-positive, and negative, respectively, which reflect the distribution of gas while forming stars.

摘要 ix
Abstract xi
Contents xiii
List of Figures xv
List of Tables xvii
1 Introduction 1
1.1 Galaxy Classification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Hubble Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.2 Kinematic Classification for Early-type Galaxies . . . . . . . . . . . . . . . . . . . . . 2
1.2 Early-type Galaxies in the Blue Cloud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 Global Properties of Star-forming ETGs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.2 The Origin of Star-forming ETGs and Their Fuel . . . . . . . . . . . . . . . . . . . . 4
2 Data and Sample Selection 5
2.1 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.1 MaNGA IFU Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.2 MaNGA Data Analysis Pipeline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.3 Galaxy Zoo 2 Morphological Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.4 SDSS Photometric Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.5 galSpec Derived Galaxy Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Sample Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Method 11
3.1 Redshift Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Calculation of Signal-to-Noise Ratio for spaxels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3 Specific angular momentum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.4 Measurement of position angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
xiii
CONTENTS
4 Results 15
4.1 Galaxy properties of SFETGs and NSFETGs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2 Morphologies of spatially resolved maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2.1 Kinematics of ionized gas and stars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2.2 Morphologies of H flux and EW maps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.3 The distributions of the properties of the four H EW morphological
types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3 The relations between local sSFR and kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.3.1 Specific angular momentum of gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.3.2 Rotation velocity difference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.4 The relations between M and Re;gas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.5 The relations between Re;gas and axis ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.6 The local sSFR-Dn4000 relation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.7 The stellar age profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5 Discussion 29
5.1 The origin of the gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.2 The morphology and kinematics of the ionized gas . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.3 The age profile of the stars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6 Summary 31
Bibliography 33
A Spatially resolved maps of SFETGs 35
B Tables of properties of the sample 53
B.1 Star-forming early-type galaxies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
B.2 Non-star-forming early-type galaxies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Baldwin, J. A., Phillips, M. M., & Terlevich, R. 1981, PASP, 93, 5
Belfiore, F., Westfall, K. B., Schaefer, A., et al. 2019, arXiv e-prints, arXiv:1901.00866
Blanton, M. R., Bershady, M. A., Abolfathi, B., et al. 2017, AJ, 154, 28
Bundy, K., Bershady, M. A., Law, D. R., et al. 2015, ApJ, 798, 7
Cappellari, M., & Copin, Y. 2003, MNRAS, 342, 345
Cappellari, M., Emsellem, E., Bacon, R., et al. 2007, MNRAS, 379, 418
Chen, C.-Y., Hwang, C.-Y., & Ko, C.-M. 2016, The Astrophysical Journal, 830, 123
Chen, H.-J. 2016, Master’s thesis, National Central University
Chown, R., Li, C., Athanassoula, E., et al. 2019, MNRAS, 484, 5192
Conselice, C. J., Bershady, M. A., Dickinson, M., & Papovich, C. 2003, AJ, 126, 1183
Davis, T. A., Alatalo, K., Sarzi, M., et al. 2011, MNRAS, 417, 882
de Vaucouleurs, G. 1948, Annales d’Astrophysique, 11, 247
Emsellem, E., Cappellari, M., Krajnović, D., et al. 2007, MNRAS, 379, 401
—. 2011, MNRAS, 414, 888
George, K. 2017, A&A, 598, A45
Graham, M. T., Cappellari, M., Li, H., et al. 2018, MNRAS, 477, 4711
Hart, R. E., Bamford, S. P., Willett, K. W., et al. 2016, MNRAS, 461, 3663
Helmboldt, J. 2007, MNRAS, 379, 1227
Huang, S., & Gu, Q.-S. 2009, MNRAS, 398, 1651
Hubble, E. P. 1926, ApJ, 64, doi:10.1086/143018
Im, M., Faber, S. M., Gebhardt, K., et al. 2001, AJ, 122, 750
Jin, Y., Chen, Y., Shi, Y., et al. 2016, MNRAS, 463, 913
Kauffmann, G., White, S. D. M., Heckman, T. M., et al. 2004, MNRAS, 353, 713
Kaviraj, S., Tan, K.-M., Ellis, R. S., & Silk, J. 2011, MNRAS, 411, 2148
Kereš, D., Katz, N., Weinberg, D. H., & Davé, R. 2005, MNRAS, 363, 2
Kewley, L. J., Groves, B., Kauffmann, G., & Heckman, T. 2006, MNRAS, 372, 961
Krajnović, D., Cappellari, M., de Zeeuw, P. T., & Copin, Y. 2006, MNRAS, 366, 787
Lagos, C. d. P., Padilla, N. D., Davis, T. A., et al. 2015, MNRAS, 448, 1271
Law, D. R., Yan, R., Bershady, M. A., et al. 2015, AJ, 150, 19
Law, D. R., Cherinka, B., Yan, R., et al. 2016, AJ, 152, 83
Lee, J. C., Hwang, H. S., & Chung, H. 2018, MNRAS, 477, 1567
Menanteau, F., Abraham, R. G., & Ellis, R. S. 2001, MNRAS, 322, 1
Menanteau, F., Ford, H., Illingworth, G., et al. 2004, ApJ, 612, 202
Moffat, A. F. J. 1969, A&A, 3, 455
Oosterloo, T., Morganti, R., Crocker, A., et al. 2010, MNRAS, 409, 500
Sage, L., Salzer, J., Loose, H.-H., & Henkel, C. 1992, A&A, 265, 19
Sánchez, S. F., Pérez, E., Sánchez-Blázquez, P., et al. 2016a, Rev. Mexicana Astron. Astrofis.,
52, 21
—. 2016b, Rev. Mexicana Astron. Astrofis., 52, 171
Schawinski, K., Lintott, C., Thomas, D., et al. 2009, MNRAS, 396, 818
Schawinski, K., Urry, C. M., Simmons, B. D., et al. 2014, MNRAS, 440, 889
Serra, P., Oosterloo, T., Morganti, R., et al. 2012, MNRAS, 422, 1835
Springel, V., Di Matteo, T., & Hernquist, L. 2005, ApJ, 620, L79
Toomre, A. 1974, in The formation and dynamics of galaxies (Springer), 347–365
Volker Beckmann, C. S. 2013, Active Galactic Nuclei (Wiley-VCH)
Westfall, K. B., Cappellari, M., Bershady, M. A., et al. 2019, arXiv e-prints, arXiv:1901.00856
Wiklind, T., Combes, F., & Henkel, C. 1995, A&A, 297, 643
Willett, K. W., Lintott, C. J., Bamford, S. P., et al. 2013, MNRAS, 435, 2835
Yan, R., Bundy, K., Law, D. R., et al. 2016, The Astronomical Journal, 152, 197
Young, L. M., Bureau, M., Davis, T. A., et al. 2011, MNRAS, 414, 940