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

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

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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 Sun 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. 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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 parallaxes 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

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