Revista Mexicana de Astronomía y Astrofísica ISSN: 0185-1101 [email protected] Instituto de Astronomía México

Teixeira, R.; De Souza, R. E.; Dos Anjos, S. IN THE LOCAL DISK Revista Mexicana de Astronomía y Astrofísica, vol. 34, 2008, pp. 64-67 Instituto de Astronomía Distrito Federal, México

Available in: http://www.redalyc.org/articulo.oa?id=57116170016

How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative © 2008: Instituto de Astronomía, UNAM - IV Reunión sobre Astronomía Dinámica en Latinoamérica Ed. Christine Allen, Alex Ruelas, & Ramachrisna Teixeira distribuci´ que 64 es A presen se se represen distribution ellas R F mosf w 05508-090, early-t represen v c Key is lo the ture, pro the tances group The theme the comp in that data; spread in b haracterized elo y rom evMexAA as w to nalan ˜ eac 1 fundamen costum partir separ´ vides The The Instituto Sc ´ same ericas, disk cit data. v para Wor selected accoun statistics is this con elo onen h h Hipparcos more formation tes y yp (Stromgren w w are traditionally of comp claramen o cit kinematic taci´ tation ds: distribution. as v arzsc kinematics e a disp on one-Gaussian S˜ elo in las de age en bre. USP ts en Man y ao often and faced t. database : sp on (Serie all tal cit of de disp de b am onen las estrellas b P hild ersi´ seis , in and On y ecifically of y aulo, y but Rua y the La 1. median the v 3 b to Astronomia, the the , distances v ersion. elo missing. on distancias groups and te with os field t kinematics the elo grup INTR of this (1907). 1987; description m de spatial for of do Brazil the three cidades la grup de on three sup uestra describ cities late-t STELLAR to the other Our Mat˜ Confer ev tempranas existencia the the , te in os mo v age, understanding mo ODUCTION erp radial olution describ It elo of Soubiran os; ([email protected]). groups. ao, spatial dos the seg del late-t yp In late-t results motion and difficult in is del stars cidades osition It se hand, ed residuales y — s´ metallicit Geof encias) 1226, color, e un ´ the olo still our do Gaussianas neigh is R. mo seleccion´ of is v prop stars. b : yp e yp elo es y el ´ of ısica motion can difieren not de solar not the vimien T the w n clearly more The Cidade e most y from e & a cities uestra eixeira, not of tip ork b Galactic grande, er the , dos stars of KINEMA single ourho Girard lo presen 34 the difficult y dep o t e motions W median core neigh obtaining w tak cal of o w kinematics in the w and , tos p esp Milky groups: o e as Univ Ci and/or e p sus de ork teresting 64–67 b endence oblaciones it represen describ 1 the e oin o v ˆ Gaussians encias disk est deal Gaussian prop ectral, of a t la erified d is b R. this propios sp 2005). acuerdo p v ersit´ prop orho t on a ailable te osition clear this of to otra fit struc- ectral for to E. W large stars with osed (2008) aria, fact la this one dis- ABSTRA the the e see A for a RESUMEN TICS the orciones. o and De taci´ appro of w y tres t- that since d con sup mejor that . ork cinem´ para p con existence and Souza, instead on opulation dynamics erp disp de ximately for w the the no la as osici´ IN la distance unas aticas it same one. ab lo these radial dev parcos accoun age, in v appro eira motions do b t CT ellos w ersi´ l est the y 1 sup magnitud, cit ofrece high published distribuci´ o out and the that distribution one and elop Our Using on THE basic y on 2007). of w describ erp 22000 de criteria with early-t ximately T t ellipsoid distin stellar e 22000 v t w de and v t o stars distance ed p S. as elo w with b fitted o osition w v from and the tip eque , o o en questions dos ork the v questions. Dos a of high cit traditionally differen the ercome LOCAL o on tas ta e yp estrellas strategy in (ESA c color, stars kinematic: y the ranged the adopted na. ˜ the temprano hange jas. the Gaussianas, 2. is to e trigonometric only De Anjos de 22000 lo for en v of and in stars elo D w based spatial a the Las v tre Hipparcos t v terv v w Souza A t Sin elo 1997) w most p ailable the elo that v cit from e consequen T kinematic o osici´ of elo 1 in that los del data T cit A dos stars describ b y al cidades. no Gaussians em o y DISK the cit difficult 6 on disp y SELECTION y arise used. only v tres on Mignard the of of b & selected Hipparcos, bargo, elo sp p allo gain y distribution? etter tres data? en t oblaciones a w w T v the disp 0.1–2.0 ectral-t ersion gal´ cit catalog tangen elo ed e grup eixeira o single ws naturally: sample v tly p ez attempted y is tard Gaussians y actica The cit the Nuestros opulations represen considered ersion us para (De b due to attained de os basically (2000) y etter and ´ yp ıos. to tial stars, residual kp sample b disp 2007. tard (ESA una describimos Souza of etter e to y las obtain se c, p another comp groups, describ Ho opulation distancia, Ho t V and ´ ersion 22392 ıos: encuen the in sola, with stars tard resultados erificamos instead the to w 1997) w v with tak with stars his v ery of & onen answ can una lac the can elo prop ´ ıas, v e como T e lying w com- stars elo with with Hip- tran k 3 w in cit eix- our ork the the v for w w w ts, de ell to er er of of of la la c- e- is y y e e e © 2008: Instituto de Astronomía, UNAM - IV Reunión sobre Astronomía Dinámica en Latinoamérica Ed. Christine Allen, Alex Ruelas, & Ramachrisna Teixeira due mine distance stars t and for said, tances, v nitude lo form magnitude lo w radial w early-t tions: (direction The a the stars alogue pleteness t to limit u v yp yp e cit cit (direction limit 3 = = = e e kno The F the data. y y to criterion times sub-gian rom for 0.15–0.30 1.40–1.60 0.00–0.15 1.15–1.40 0.30–0.45 0.85–1.15 of stars a with this w the v are v v distribution yp 3. v w the ere (ESA r limit kinematic r r prop late of B–V SELECTED elo 100 comp the e and cos D all sin sin these tangen greater obtained Of is to 60-90 B–V the cit group mixed A and w and km t er of done T the b l l ere residual of t yp y North course, 1997) of onen prop A , cos cos v stars. + motions increasing comp e the elo 3 color. b s as SPECTRAL-TYPE distance tial TREA observ ed not km − v et than stars, c study b b of b b 1 ts, er cit haracteristics in w indicated from y as Hipparcos in Galactic that − − comp cos een T in onen late-t s D y considered motion, v the to eac − Th u ABLE Sp v v Mignard elo function A 70% ational TMENT disp 1 this and to b b M0–M5 K5–M0 b K0–K5 T A0–A5 only (Galactic A5–F0 the F0–F5 sp 0.45–0.85 us, and ec. h corresp dep cit . ts fit A onen Galactic cos sin yp w ectral direction. ersion based y w radial GR w ork observ of the t e, . ending P l the 1 in for l yp a e from ts, ole) data, y satellite Here sin a sin as OUPED can , of (2000) e onds the only STRA here. main-sequence of the w observ t single v in on yp b Galactic v cen b ational sho e w l longitude) of this KINEMA whic elo describ and w ere that are the follo + on es: − stars the with the appro ter w e In TEGY cities. v also v ational In comp w sample. Gaussian the l not h able l disk. 3 in BY wing N v 2285 3350 4202 6533 3185 2837 general, T ork is, spatial direction), cos b quan sin w for groups star turn, yc , the e ximately latitude, T imp e sp selected and the ho the ells TICS able to l l with and These deter- whic ectral , , equa- gian tities mag- osed p cat- late dis- the the v v us, (1) er- as to of e- e- 1. w h a t IN THE tailed tors sions w σ & disp w where to the of sp anisotrop This radial w not stacle sions sphere the squares theme, sector. are h tribution other for describ can tial lo and σ yp v v 2 2 as e e cit LOCAL l b onding T the a w divided As These Th T In the otesis obtain Galactic obtain eixeira not comp directions ersions y = v ha small = to o ould is b σ σ w us, distribution the w : v dev ving a v dev v s v t e imp Γ ords,  w elo the most  as 3.1 (v l l metho elo e (v in the v consequence ork y cos and onen cos and in to w b using elopmen ha to l distributions elop n presen cit . DISK w the Γ ) ) the cit osing a (2007). parameters the ork um same in = σ v 2 the v the e El 2 v 2 comp y cen u w fixed with y of e elo l σ l = = σ ts eac d, , can statistic individual lipsoid b of e ellipsoid sin v had this σ v celestial + in measuremen σ er equation b ter the radial direction b are cit u t of the on v h as sectors /σ sin 2 are from t ensate √ √ equal case, of smaller see for y direction. b sector and the only direction. strategy of v 2 2 stars. w sa eac 2 + v ellipsoid, stars. π π 1 1 constan of alues velo orking l ying the direction.  in and σ σ this quan sin spatial that h whic in pro σ w v v sphere the area a σ v b l v w for (3) city e the of ab sector 2 u 2 elo terms l tangen few sectors, vide So, Γ exp that Ho l formalism of ha , exp (equation tities Γ ts and h out the lac sin describ v 2 w the with cit w t w sectors literature, v σ determination T w w from e stars e motion man e in w k in u 2 o y ev e  300 cen the  need the , the e = of v obtain b no fact tial of σ for − eac obtain o b − σ 72 er, the + construct u v but y v the ter only e are 2 , 2 distance ercome radial stars. p σ v v hip eac h σ and equal σ cos σ of v ev comp elo er that v w elo u the to 3). pro v see Γ v l v 2 v /σ b 2 of sector. disp orks l en b in fixed, w 2 l the h b othesis 2 and 2 sector. cit cit 2 the mak are the y w  and σ the jected b  ob disp De if F this The v w onen v y  y area the ersion or , l elo celestial this are . ject, tangen- σ w on the limited in σ e and/or v disp disp and sector. w v e ersion Souza elo corre- u 2 Here, a cities some b case, ideal least ts eac that can- that , . this sec- dis- ob- the de- v (2) ciy er- er- w 65 In v in v e- (3) h e b l © 2008: Instituto de Astronomía, UNAM - IV Reunión sobre Astronomía Dinámica en Latinoamérica Ed. Christine Allen, Alex Ruelas, & Ramachrisna Teixeira s b w tic b This tributions where v after another mined els), group. sian Fig. 66 (v l y een ork

3.2 N N and δN 200 400 600 800 δN 200 400 600 800 -20 -20 20 20 rotation, l the The Since In ) 0 0 1. for (upp . subtraction and figure, done as Figure v V -80 α in sup Marginal b one elo residual s t describ of is 4. (v in (v Mignard er t the obtained (v erp city b in a -40 the l eac RESUL group ) ) panels) for b where prop 1 ) osition most radial h w distribution = = w late-t ed whic v v sector, 0 e v e l elo of ortionalit elo of represen can with (2000). TS α α cases, δ using cit the h and the yp cities s t 40 v N two of 1 1 elo w y (v see A0A5 AND (v e but e t solar the corresp distributions early-t w b cities l stars t Gaussians 80 used the ) ) w instead o the t v y + + by here, o l marginal the Gaussians: DISCUSSION co and (1 motion (1 t Gaussians -80 w marginal the the (K0K5) yp are efficien onds o − v − differen elo e mo v TEIXEIRA, α α sup a parameters -40 b stars not ) ) cit single t s w ( dels, to and 2 v erp distribution 2 t. ere y (v l (v as v a 0 the v and (A0A5) distribution tly b (lo b osition v l elo ) ) the ailable calculated one examples. , , Gaussian w than cit 40 v residual er b Galac- ). Gaus- deter- y DE pan- of and dis- ( has 80 (4) w left of e SOUZA, ) Early-t σ prop p σ the riously where ulations ( star 40 w in groups easily distribution star of as K0K5 no one; σ v v ersion

ell-defined N N 100 200 300 400 500 600 100 200 300 400 500 600 teresting δN δN -20 -20 & u yp 20 20 for the ≈ km In Apart 0 0 ≈ significan ≈ same groups, ortions DOS e group: b 13 -80 oth 13 the note 20 stars this , group, fit, as are s w p . − . are 0 0 km opulation e 1 v from ANJOS other for results -40 ) km sho alues table sho km note the A0A5 results the giv b kinematic and the t one s y − as ws example wn gain s en 1 s b the the − v scenario 0 t ). − l that same etter w obtained w w 1 another of group. that are 1 in b ell e o W and t ha y gain using and 40 high concerning w early-t clearly T e v the as the ving o-Gaussian able K0K5 represen in can ery for p in σ opulations is σ ( for in 80 w the right v late-t parameter w of t here the quite similar. also Biena elo w yp mean 2. ≈ the see the ≈ o lo -80 three e cit 7 ) w tation A0A5 Gaussians yp see . 5 star represen Late-t ( 0 the y differen ym other . σ the 4 v σ e mo km -40 u elo disp u that Ho km in groups; ´ lo e groups, ≈ presence ≈ del. α cit w yp of group, late-t (1999) s eac w t ersion − 19 v 20 0 c w s the e t ev y v b tation the 1 hange. − elo o h and . ) stars . er, 3 1 instead disp 6 yp and late-t late-t t 40 only cit presen km km w w v as for w ( elo e of ( e o ersion σ y σ K0K5 other e ha p u else- u s s w star 80 cit Cu- dis- yp yp t can the the op- − − w ell v of ts ≈ ≈ 1 1 y o e e e , , © 2008: Instituto de Astronomía, UNAM - IV Reunión sobre Astronomía Dinámica en Latinoamérica Ed. Christine Allen, Alex Ruelas, & Ramachrisna Teixeira 21 t and 13 data tak group. b late-t of from that long yp etter . . the 3 3 es e Since Our km to the Mignard km stars as yp the in thic represen the On e a to s results t Galactic − s w our stars. consequence − k 1 using o thin the accoun 1 , disk. kinematic σ and v stars (2000) other ts disk, ≈ sho the 5. W plane M0M5 K5M0 σ 11 t K0K5 group the e w CONCLUSION w are the single . with hand, in 3 that ≈ ( of p v km terpret σ of elo VELOCITY opulations concen u 8 spread the a . less s 4 cit Gaussian the the − ≈ negligible N 1 km 2285 3350 6533 fact y star and than this 19 trated v t distribution w ery of s . s 8 that o-Gaussian − σ detected 1 b KINEMA 600 age w km remark ) mo etter ELLIPSOID con α ≈ at for our 74 65 57 (%) p del. inside 9 s tamination c a − . the 0 fit approac it 1 able distance here km , for TICS is to mo σ early- σ 41 41 40 18 20 23 clear v eac s fact u − the the b del ...... T 28 25 66 54 02 11 1 e- ≈ (km FR h h ) IN ABLE       OM THE s 5 5 4 4 3 2 − ...... 20 19 48 34 33 31 1 TW differen Biena simply De Mignard, Stromgen, lations ESA Soubiran, rise group Sc that ) 2 LOCAL h SP-1200 Carsw w Souza, O to arzsc σ 31 26 27 16 13 the 1997, ym 9 v GA of ...... t 09 w b 27 79 29 28 59 the (km ´ e, same y ell momen F. e hild, late-t C., USSIAN R. B.  O.      The DISK the found (No (Dordrec 2000, follo 2 s 3 3 3 2 1 E., & 1987, 1999, − ...... K. p 24 95 38 02 73 38 yp ordwijik: 1 spread Hipparcos Girard, opulations ) & wing ts 1907, e A&A, the REFERENCES T in of A&A, stars MODEL eixeira, h σ 17 19 19 t: NA star 5 5 5 late-t w question: Gottingen of P ...... Reidel), 354, 27 78 05 42 93 64 ESA) . TO (km in 341, 2005, and age, formation?    are    yp R. a 522 ASI, 1 0 1 2 2 2 s 86 w T e . . . − . . . 2007, clearly 02 64 34 21 52 18 or A&A, 229 yc ell 1 groups ) Nac can ed. ho w defined e A&A, hr., Catalogues, G. 438, the presen are b Gilmore 614 e seeing 139 t 471, w w explained t o a y in p 475 giv & opu- eac ESA t w 67 R. es h o