a proper motion study of the lupus clouds using vo tools (a collaboration with the svo) francisco...

A proper motion study of the Lupus clouds using VO tools

(a collaboration with the SVO)

Francisco Jiménez Esteban (CAB & SVO)Belén López Martí (CAB) & Enrique Solano (CAB & SVO)

Gaia: II Reunión Científica de la REG, Santillana del Mar, September 2011

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 2

The Lupus clouds

One of the nearest low-mass star forming regions

d=140-220 pc

age<5 Myr

Star-count map by

Cambrésy et al. (1999)

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 3

The Lupus cloudsWithin or near the Gould Belt

xx

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 4

The Lupus cloudsThe stellar & substellar population: Most recent results

A large increase of the stellar and substellar population(but few spectra so far)

• Comerón (2008):

– Review of previous results.

– Lists 74 known members of Lup 1, 2, 3 & 4

• Merín et al. (2008):

– Spitzer c2d census of 159 PMS stars & candidates in Lup 1, 3 & 4

– Mostly objects with disks and/or envelopes

• Comerón et al. (2009):

– ~130 new cool, ~without envelope or disk, very low-mass members in Lup 1, 3 & 4.

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 5

Proper motions of Lupus members

• Sample: Compilation from Comerón (2008), Merín et al. (2008) & Comerón et al. (2009) 331 objects

• Method:– Multiple Cone Search using TOPCAT– Matching radius: 2– Astrometric catalogues: USNO-B1, SSS, PPMX and UCAC3– Purge resulting catalog using UCAC3 information:

• Errors != 0• Useful observations >3

Final sample: 178 objects

Goal: To check membership of proposed Lupus candidate members

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 6

Proper motions of Lupus members

Two kinematic groups!

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 7

Proper motions of Lupus membersLupus 1:The two groups have different

spatial distributions and proper motion directions.

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 8

Proper motions of Lupus membersLupus 3:The two groups have different

spatial distributions and proper motion directions.

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 9

Proper motions of Lupus membersLupus 4:The two groups have different

proper motion directions.

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 10

Proper motions of Lupus members

Group B is formed mostly by diskless stars, while Group A contains sources with and without disks.

Group B, as a whole, represent a later evolutionary stage than Group A.

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 11

Proper motions of Lupus members

The Group B sources tend to be brighter and redder than the Group A sources.

Their infrared colours are consistent with reddened background giants

(but also with reddened late K and early M-type stars).

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 12

Proper motions of Lupus membersComparison with Gould Belt populations

ROSAT Gould Belt stars (Wichmann et al. 1997) Upper Scorpius members (Bouy & Martín 2009)

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 13

Properties of Lupus kinematic membersGroup A sources with and without disks

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 14

Properties of Lupus kinematic membersEffective temperature

No trend (better precision required)

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 15

Properties of Lupus kinematic members

Physical parameters

No trend (better precision required)

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 16

Conclusions

• We have found two distinct kinematic groups in our compiled catalog of Lupus candidate members.

• The properties of the Group B sources (lower proper motions, location outside the cloud cores, virtual lack of sources with disks, optical and near-infrared colours) suggest that they are a background population or mixture of populations unrelated to the Lupus clouds.

• Group A sources have properties consistent with them being a genuine population of the Lupus clouds. Their proper motions are also consistent with those of other Gould Belt populations.

• We find no correlations between the proper motions and the properties of the Group A sources. More accurate measurements are required (Gaia).

Gaia: II Reunión Científica de la REG, Santillana del Mar, Sept 2011 17

More details in

López Martí et al., 2011, A&A, 529, A108

More details in

López Martí et al., 2011, A&A, 529, A108