Post on 15-Dec-2015
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
A multiwavelength analysis of Blue Compact Dwarf GalaxiesA multiwavelength analysis of Blue Compact Dwarf Galaxies
Ángel R. López-SánchezÁngel R. López-SánchezCSIRO /Australia Telescope National Facility (ATNF, Australia)
Bärbel Koribalski (CSIRO/ATNF), Bärbel Koribalski (CSIRO/ATNF), César Esteban (IAC), Janine van Eymeren (U. Manchester), César Esteban (IAC), Janine van Eymeren (U. Manchester),
Attila Popping (CSIRO/ATNF) & John Hibbard (NRAO)Attila Popping (CSIRO/ATNF) & John Hibbard (NRAO)
Galaxy Metabolism – Sydney – 24 June 2009
Ángel R. López-SánchezÁngel R. López-SánchezCSIRO /Australia Telescope National Facility (ATNF, Australia)
Bärbel Koribalski (CSIRO/ATNF), Bärbel Koribalski (CSIRO/ATNF), César Esteban (IAC), Janine van Eymeren (U. Manchester), César Esteban (IAC), Janine van Eymeren (U. Manchester),
Attila Popping (CSIRO/ATNF) & John Hibbard (NRAO)Attila Popping (CSIRO/ATNF) & John Hibbard (NRAO)
Galaxy Metabolism – Sydney – 24 June 2009
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Blue Compact Dwarf Galaxies (BCDGs)Blue Compact Dwarf Galaxies (BCDGs)
Subset of low-luminosity (MB -18) and low metallicity (~10 % solar) galaxies undergoing a strong and short-lived episode of star formation.
Quickly gas consumption – unlike spirals, star formation occurs
in transient, sporadic bursts. Compact, irregular morphologies Intense narrow emission lines superposed on
a blue continuum (i.e. Thuan 1991).– Sometimes, Wolf-Rayet features!
The starbust and a very young stellar population dominate the optical light (Cairós et al. 2001), very often masking all evidence of the underlying older stellar population,
– NIR photometry is sometimes needed to separate both components (Noeske et al. 2003).
However, the origin and peculiar nature of their starburts is still poorly understood.
Subset of low-luminosity (MB -18) and low metallicity (~10 % solar) galaxies undergoing a strong and short-lived episode of star formation.
Quickly gas consumption – unlike spirals, star formation occurs
in transient, sporadic bursts. Compact, irregular morphologies Intense narrow emission lines superposed on
a blue continuum (i.e. Thuan 1991).– Sometimes, Wolf-Rayet features!
The starbust and a very young stellar population dominate the optical light (Cairós et al. 2001), very often masking all evidence of the underlying older stellar population,
– NIR photometry is sometimes needed to separate both components (Noeske et al. 2003).
However, the origin and peculiar nature of their starburts is still poorly understood. SBS 1054+365 (ALFOSC @ NOT, U
+ B + V)
IC 4662 (EMMI @ NTT, B + R + H)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Á.R. López-Sánchez PhD Thesis (2006) supervised by C. Esteban (IAC)
Á.R. López-Sánchez PhD Thesis (2006) supervised by C. Esteban (IAC)
Massive star formation in Wolf-Rayet galaxies
Massive star formation in Wolf-Rayet galaxies
See López-Sánchez & Esteban, 2008, paper I (A&A 491, 131) and II (2009, in rev.)
and III (2009, in prep.).
See López-Sánchez & Esteban, 2008, paper I (A&A 491, 131) and II (2009, in rev.)
and III (2009, in prep.).
We completed a detailed analysis of a sample of 20 Wolf-Rayet galaxies (many of them BCDGs) combining deep optical and NIR broad band and H imaging together with optical spectroscopy (long slit and echelle) data + UV, HI, FIR from literature.
We completed a detailed analysis of a sample of 20 Wolf-Rayet galaxies (many of them BCDGs) combining deep optical and NIR broad band and H imaging together with optical spectroscopy (long slit and echelle) data + UV, HI, FIR from literature.
Our multiwavelength analysis revealed that the majority of studied objects (16 up to 20) shows features such as plumes, tails, TDGs, regions
with very different chemical abundances inside galaxies, perturbed kinematics of the ionized gas or lack of neutral hydrogen gas,
suggesting that interactions have played an important role in the triggering mechanism of the observed star-formation bursts.
Our multiwavelength analysis revealed that the majority of studied objects (16 up to 20) shows features such as plumes, tails, TDGs, regions
with very different chemical abundances inside galaxies, perturbed kinematics of the ionized gas or lack of neutral hydrogen gas,
suggesting that interactions have played an important role in the triggering mechanism of the observed star-formation bursts.
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Interferometric H I observations of BCDGsInterferometric H I observations of BCDGs
H I observations of BCDGs: Single-dish HI surveys (i.e. Thuan et al. 1999;
HIPASS, Koribalski et al. 2004; Huchtmeier et al. 2005; 2007)
Still not many high-resolution HI studies! And giving unexpected surprises.
Importance of interf. HI observations:
H I morphology and estimation of neutral gas mass globally and locally (clumps),
Analysis of the H I kinematics (rotation or turbulence behaviour, total mass, dark matter),
Neutral hydrogen gas is the best tracer for galaxy-galaxy interactions !!!
Combining H I results with other parameters (absolute luminosity, SFR, stellar and dust content, oxygen abundance...)
provide powerful clues about the nature and evolution of BCDGs.
H I observations of BCDGs: Single-dish HI surveys (i.e. Thuan et al. 1999;
HIPASS, Koribalski et al. 2004; Huchtmeier et al. 2005; 2007)
Still not many high-resolution HI studies! And giving unexpected surprises.
Importance of interf. HI observations:
H I morphology and estimation of neutral gas mass globally and locally (clumps),
Analysis of the H I kinematics (rotation or turbulence behaviour, total mass, dark matter),
Neutral hydrogen gas is the best tracer for galaxy-galaxy interactions !!!
Combining H I results with other parameters (absolute luminosity, SFR, stellar and dust content, oxygen abundance...)
provide powerful clues about the nature and evolution of BCDGs.
II Zw 40 - B + HI contours
van Zee et al 1998
NGC 2915 – HI (blue) + B (green) + R (red)
Meurer et al. 1996
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Observations of BCDGs using the ATCAObservations of BCDGs using the ATCA
Australia Telescope Compact Array, 6 x 22m dishes, Narrabri, NSW, Australia Deep H I line & 20 cm radio continuum observations for a sample of BCDGs
– NGC 1510*– NGC 5253*
Australia Telescope Compact Array, 6 x 22m dishes, Narrabri, NSW, Australia Deep H I line & 20 cm radio continuum observations for a sample of BCDGs
– NGC 1510*– NGC 5253*
– POX 4– He 2-10
– POX 4– He 2-10
– Tol 9– Tol 30
– Tol 9– Tol 30
– IC 4662*– IC 4870
– IC 4662*– IC 4870
– Tol 1924-416– ESO 108-G017
– Tol 1924-416– ESO 108-G017
Full 12h x 4 arrays: EW 367m, 750m, 1.5km, 6 km
– Velocity resolution of 4 km/s
– HI column density:
~ 5 x 1019 cm-2 (for 40” beam)
– Angular resolution of ~20”
Observations were completed on Feb 2009
* Belonging to the Local Volume HI Survey (LVHIS) project, PI B. Koribalski
Full 12h x 4 arrays: EW 367m, 750m, 1.5km, 6 km
– Velocity resolution of 4 km/s
– HI column density:
~ 5 x 1019 cm-2 (for 40” beam)
– Angular resolution of ~20”
Observations were completed on Feb 2009
* Belonging to the Local Volume HI Survey (LVHIS) project, PI B. Koribalski
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
The galaxy NGC 5253The galaxy NGC 5253
DHel= 4.0 Mpc (Karachentsev et al. 2004)
Scale: 19 pc / arcsec Optical size: 5.0’ 1.9’ Classified as Im pec, H II
starburst (NED), BCDG One of the closest
starbursts, observed at all wavelengths
It belongs to the M83 subgroup of the Centaurus Group
Deep analysis of its ionized gas using UVES@VLT López-Sánchez et al. 2007
DHel= 4.0 Mpc (Karachentsev et al. 2004)
Scale: 19 pc / arcsec Optical size: 5.0’ 1.9’ Classified as Im pec, H II
starburst (NED), BCDG One of the closest
starbursts, observed at all wavelengths
It belongs to the M83 subgroup of the Centaurus Group
Deep analysis of its ionized gas using UVES@VLT López-Sánchez et al. 2007
NGC 5253 – B (blue) + V (green) + I (red) 2.5m du Pont telescope, Las Campanas Observatory, combined by Á.R. López-Sánchez
8.8’
NGC 5253 – V (blue) + I (green) + H (red) 2.5m du Pont telescope, LCO (V, I) + 1.5m CTIO (H) combined by Á.R. López-Sánchez
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
NGC 5253: Deep VLT echelle spectroscopyNGC 5253: Deep VLT echelle spectroscopy
4 independent regions analized in detail:
• Physical conditions: Ne, Te, reddening.
• Chemical abundances: O, N, Ne, S, Cl, Ar, Fe, He, C
• Kinematics of the ionized gas
169 emission lines identified in region B
2 main results:
The confirmation of a localized chemical pollution,
The detection of O and C recombination lines.
4 independent regions analized in detail:
• Physical conditions: Ne, Te, reddening.
• Chemical abundances: O, N, Ne, S, Cl, Ar, Fe, He, C
• Kinematics of the ionized gas
169 emission lines identified in region B
2 main results:
The confirmation of a localized chemical pollution,
The detection of O and C recombination lines.
López-Sánchez, Esteban, García-Rojas, Peimbert &
Rodríguez 2007, ApJ 656, 168and López-Sánchez PhD Thesis
López-Sánchez, Esteban, García-Rojas, Peimbert &
Rodríguez 2007, ApJ 656, 168and López-Sánchez PhD Thesis
NGC 5253 – WFPC @ HST
UV (blue) + H (green) + [S II] (red) Combined by Á.R. López-Sánchez
12+log O/H = 8.28 log N/O = – 1.50
12+log O/H = 8.18 log N/O = –
0.91
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
New radio data of NGC 5253 from the LVHIS (Local Volume HI Survey) project using four different ATCA arrays
Properties: H I flux: 31.1 1.5 Jy km/s H I mass: (8.0 0.4) 107 M
Dynamical mass: ~108 M
López-Sánchez, Koribalski & Esteban 2007
New radio data of NGC 5253 from the LVHIS (Local Volume HI Survey) project using four different ATCA arrays
Properties: H I flux: 31.1 1.5 Jy km/s H I mass: (8.0 0.4) 107 M
Dynamical mass: ~108 M
López-Sánchez, Koribalski & Esteban 2007
NGC 5253: H I radio dataNGC 5253: H I radio data
NGC 5253 – H I map (blue) + R (green) + H (red)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
NGC 5253: H I radio dataNGC 5253: H I radio data ESO 154-G023 ATCA H I velocity field
ESO 154-G023 ATCA H I velocity field
H I velocity field:
Rotating about the optical MAJOR axis? Any kind of outflow? Formation of a polar ring? Interaction with M83 ~1 Gyr ago?
Disruption/accretion of a gas-rich companionKinematics of the ionized gas decopled from kinematics of stars?
H I velocity field:
Rotating about the optical MAJOR axis? Any kind of outflow? Formation of a polar ring? Interaction with M83 ~1 Gyr ago?
Disruption/accretion of a gas-rich companionKinematics of the ionized gas decopled from kinematics of stars?
H I velocity field:
Rotating about the optical MAJOR axis?
H I velocity field:
Rotating about the optical MAJOR axis?
López-Sánchez, Koribalski & Esteban 2007 and Kobulnicky & Skillman 2008López-Sánchez, Koribalski & Esteban 2007 and Kobulnicky & Skillman 2008NGC 5253 ATCA H I velocity field NGC 5253 ATCA H I velocity field
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Klemola 13 group (HIPASS J1034-28)
Located at 43.3 Mpc
Tol 9 (ESO 436-42) is a starburt WR galaxy
ESO 436-46 is a spiral at 20 kpc from Tol 9.
Several objects surrounding Tol 9.
2 slit positions using 2.5m INT & 2.56m NOT.
Chemical abundances using direct method:
– 12+log O/H = 8.57±0.10
– log N/O = – 0.81 ± 0.11
Klemola 13 group (HIPASS J1034-28)
Located at 43.3 Mpc
Tol 9 (ESO 436-42) is a starburt WR galaxy
ESO 436-46 is a spiral at 20 kpc from Tol 9.
Several objects surrounding Tol 9.
2 slit positions using 2.5m INT & 2.56m NOT.
Chemical abundances using direct method:
– 12+log O/H = 8.57±0.10
– log N/O = – 0.81 ± 0.11
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
López-Sánchez & Esteban (2008, 2009)López-Sánchez & Esteban (2008, 2009)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Our new deep images reveal a bridge towards a dwarf companion object at 10 kpc.
– Composed by an OLD pop.
Our new deep images reveal a bridge towards a dwarf companion object at 10 kpc.
– Composed by an OLD pop.
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
Deep V image, ALFOSC @ 2.56m NOT López-Sánchez (2006)
López-Sánchez & Esteban (2008)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Our new deep images reveal a bridge towards a dwarf companion object at 10 kpc.
– Composed by an OLD pop.
H image reveals on-going star formation activity and a filamentary structure.
Our new deep images reveal a bridge towards a dwarf companion object at 10 kpc.
– Composed by an OLD pop.
H image reveals on-going star formation activity and a filamentary structure.
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
Continuum-substracted H image, ALFOSC @ 2.56m NOT López-Sánchez (2006)
López-Sánchez & Esteban (2008)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Tol 9 and surroundingsTol 9 and surroundings
López-Sánchez & Esteban (2008)López-Sánchez & Esteban (2008)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
Tol 9
The kinematics of the ionized gas was studied via the analysis of emission line profiles of our spectra.
The kinematics of the ionized gas was studied via the analysis of emission line profiles of our spectra.
– PA 49º: Strange velocity pattern that can not be attributed to rotation.
– PA 49º: Strange velocity pattern that can not be attributed to rotation.
– PA 109º: It crosses the filamentary H structure, showing a very intriguing behaviour:
a bipolar bubble expanding at about 80 km s-1?
– PA 109º: It crosses the filamentary H structure, showing a very intriguing behaviour:
a bipolar bubble expanding at about 80 km s-1?
PA 49ºPA 109º
López-Sánchez & Esteban (2009)López-Sánchez & Esteban (2009)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
HIPASS reveals a considerable amount of atomic gas, probably mostly associated with ESO 436-46.
HIPASS reveals a considerable amount of atomic gas, probably mostly associated with ESO 436-46.
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
We obtained ATCA H I ob-servations in 6 km, 1.5 km, 750m and 350m arrays
We obtained ATCA H I ob-servations in 6 km, 1.5 km, 750m and 350m arrays
Also cont. observations at 20, 13, 6 and 3 cm.
Also cont. observations at 20, 13, 6 and 3 cm.
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
H I distribution
Total HI mass:– MHI: 3.1 109 M
Tol 9 cloud:– MHI: 2.2 109 M
– MHI/LB = 0.21
– MDyn/LB = 18.8
ESO 436-46:– MHI: 8.7 108 M
– MHI/LB = 0.07
– MDyn/LB = 10.4
Tail:– MHI: 6.0 107 M
H1032-2819:– MHI: 3.5 107 M
H I distribution
Total HI mass:– MHI: 3.1 109 M
Tol 9 cloud:– MHI: 2.2 109 M
– MHI/LB = 0.21
– MDyn/LB = 18.8
ESO 436-46:– MHI: 8.7 108 M
– MHI/LB = 0.07
– MDyn/LB = 10.4
Tail:– MHI: 6.0 107 M
H1032-2819:– MHI: 3.5 107 M
78” x 32” 78” x 32”
Tail
Tol 9
ESO 436-46
H 1032-2819
López-Sánchez et al. In prep.López-Sánchez et al. In prep.
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
WR galaxy Tol 9 within the Klemola 13 groupWR galaxy Tol 9 within the Klemola 13 group
H I kinematics
ESO 436-46:– MDyn: 1.7 1011 M
– MDyn/LB = 10.4
Tol 9 cloud:– Disturbed kin. at E
– MDyn: 2.0 1011 M
– MDyn/LB = 18.8
Tail: - – Cte velocity
H I kinematics
ESO 436-46:– MDyn: 1.7 1011 M
– MDyn/LB = 10.4
Tol 9 cloud:– Disturbed kin. at E
– MDyn: 2.0 1011 M
– MDyn/LB = 18.8
Tail: - – Cte velocity
78” x 32” 78” x 32”
Tail
Tol 9
ESO 436-46
H 1032-2819
PA 273º
PA 192º
López-Sánchez et al. In prep.López-Sánchez et al. In prep.
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Tol 30 – B (blue) + R (green) + H (red) ALFOSC @ 2.6m NOT
WR galaxy Tol 30WR galaxy Tol 30
Tol 30 – B (blue) + V (green) + R (red) WFC @ 2.5m INT Tol 30 – H I map (blue) + B (green) + R (red)
D = 29.3 Mpc 1’ = 8.5 kpc Optical size: 1.2’ 1’ Two intense
star-forming regions in opposite places within the galaxy
Optical imagery and ionized gas analysis using 2.56m NOT:
– WR features
– 12+log O/H = 8.07
– log N/O = – 1.5
Deep optical imagery using WFC @ 2.5m INT
– Detection of nearby and diffuse non-stellar objects
D = 29.3 Mpc 1’ = 8.5 kpc Optical size: 1.2’ 1’ Two intense
star-forming regions in opposite places within the galaxy
Optical imagery and ionized gas analysis using 2.56m NOT:
– WR features
– 12+log O/H = 8.07
– log N/O = – 1.5
Deep optical imagery using WFC @ 2.5m INT
– Detection of nearby and diffuse non-stellar objects
López-Sánchez et al. In prep.López-Sánchez et al. In prep.
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
WR galaxy Tol 30WR galaxy Tol 30
Tol 30 – H I map (blue) + B (green) + R (red)
H I distribution
Total HI mass:– MHI: 1.4 109 M
Tol 30 MB:– MHI: 1.1 109 M
– MHI/LB = 1.2– MDyn/LB = 17.1
Northern tail:– MHI: 2.1 108 M
– 15% total HI mass
Eastern tail:– MHI: 9.1 107 M
– 7% total HI mass TDG or dwarf obj?:
– MHI: 2.3 107 M
– MHI/LB = 0.12– It shows rotation!– MDyn/LB = 7.3
H I distribution
Total HI mass:– MHI: 1.4 109 M
Tol 30 MB:– MHI: 1.1 109 M
– MHI/LB = 1.2– MDyn/LB = 17.1
Northern tail:– MHI: 2.1 108 M
– 15% total HI mass
Eastern tail:– MHI: 9.1 107 M
– 7% total HI mass TDG or dwarf obj?:
– MHI: 2.3 107 M
– MHI/LB = 0.12– It shows rotation!– MDyn/LB = 7.3
López-Sánchez et al. In prep.López-Sánchez et al. In prep.
Tol 30
?
Northern tail
Eastern tailTol 30 dwarf – B (blue) + R (green) + H (red)1 frame 150s per filter, not reducedObservations at 2.3m ANU 2 nights ago!
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
The galaxy pair NGC 1512 / 1510The galaxy pair NGC 1512 / 1510 NGC 1512:
– SB(r)ab, Z ~0.7 Zo– D = 9.5 Mpc– Bar ~ 3’ = 8.3 kpc– Ring ~ 3’ x 2’
= 8.3 x 5.5 kpc– Nuclear ring ~ 16” x 12”
(740 x 550 pc) NGC 1510:
– S0, BCD, WR, Z~0.2 Zo– Probable N enrichment– 5’ = 13.8 kpc
from NGC 1512 H images (Meurer et al.
2006) reveal many star forming regions
– Sizes 2”–5” (90–230 pc)– Dozens in the ring – NGC 1510– But also in external
regions with no evident continuum emission!
NGC 1512: – SB(r)ab, Z ~0.7 Zo– D = 9.5 Mpc– Bar ~ 3’ = 8.3 kpc– Ring ~ 3’ x 2’
= 8.3 x 5.5 kpc– Nuclear ring ~ 16” x 12”
(740 x 550 pc) NGC 1510:
– S0, BCD, WR, Z~0.2 Zo– Probable N enrichment– 5’ = 13.8 kpc
from NGC 1512 H images (Meurer et al.
2006) reveal many star forming regions
– Sizes 2”–5” (90–230 pc)– Dozens in the ring – NGC 1510– But also in external
regions with no evident continuum emission!
NGC 1512: – SB(r)ab, Z ~0.7 Zo– D = 9.5 Mpc– Bar ~ 3’ = 8.3 kpc– Ring ~ 3’ x 2’
= 8.3 x 5.5 kpc– Nuclear ring ~ 16” x 12”
(740 x 550 pc)
NGC 1512: – SB(r)ab, Z ~0.7 Zo– D = 9.5 Mpc– Bar ~ 3’ = 8.3 kpc– Ring ~ 3’ x 2’
= 8.3 x 5.5 kpc– Nuclear ring ~ 16” x 12”
(740 x 550 pc)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
H I in NGC 1512 / 1510H I in NGC 1512 / 1510 ATCA observ.
using 7 arrays Mosaic using
4 pointings
Total int. time: 3.11 days
Huge amount of neutral gas!
Two extended spiral arms
Two TDG candidates
NGC 1512:
NGC 1510:
ATCA observ. using 7 arrays
Mosaic using 4 pointings
Total int. time: 3.11 days
Huge amount of neutral gas!
Two extended spiral arms
Two TDG candidates
NGC 1512:
NGC 1510:
Koribalski & López-Sánchez (2009, MNRAS)Koribalski & López-Sánchez (2009, MNRAS)
NGC 1512NGC 1512
NGC 1510NGC 1510
TDGTDG
TDGTDG
– MHI = 5.7109 M
– MDyn~ 4 x 1011 M
– MHI/LB = 1
– MHI ~ 4x107 M
– MHI/LB ~0.07
– MHI = 5.7109 M
– MDyn~ 4 x 1011 M
– MHI/LB = 1
– MHI ~ 4x107 M
– MHI/LB ~0.07
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
H I / UV comparison in NGC 1512/1510H I / UV comparison in NGC 1512/1510
Koribalski & López-Sánchez (2009, MNRAS, in rev.)Koribalski & López-Sánchez (2009, MNRAS, in rev.)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
NGC 1512 / 1510 Rotation fit and residues
NGC 1512 / 1510 Rotation fit and residues
The velocity field is mainly rotation,
But we found some discrepances in the most external regions and in the position of NGC 1510.
Star formation activity and the external HI structures seem to be consequence of the interaction that NGC 1512 and NGC 1510 are experiencing. Minor merger ~ 400 Myr
The velocity field is mainly rotation,
But we found some discrepances in the most external regions and in the position of NGC 1510.
Star formation activity and the external HI structures seem to be consequence of the interaction that NGC 1512 and NGC 1510 are experiencing. Minor merger ~ 400 Myr
Koribalski & López-Sánchez 2009, MNRAS
NGC 1512 / 1510 also include in the THING project, with higher spatial resolution
(Deane & de Blok, in prep)
Koribalski & López-Sánchez 2009, MNRAS
NGC 1512 / 1510 also include in the THING project, with higher spatial resolution
(Deane & de Blok, in prep)
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
Further tidal tails features in BCDGsFurther tidal tails features in BCDGs IC 4870– D = 10.2 Mpc– Optical prop:
35” compact core,Elliptical low-luminosity
component 1.4’x0.4’
– H I reveals two long tails 3.7’ (N) and 4.2’(S)
Knot in S tail has ~14% of the neutral mass.
– Merger of two independent HI clouds?
ESO 108-G017– D = 28.2 Mpc– Faint optical tail– HI is +5 times optical size!– Elongated HI cloud
with some disturbed kinematics
IC 4870– D = 10.2 Mpc– Optical prop:
35” compact core,Elliptical low-luminosity
component 1.4’x0.4’
– H I reveals two long tails 3.7’ (N) and 4.2’(S)
Knot in S tail has ~14% of the neutral mass.
– Merger of two independent HI clouds?
ESO 108-G017– D = 28.2 Mpc– Faint optical tail– HI is +5 times optical size!– Elongated HI cloud
with some disturbed kinematics
He 2-10: Extended HI emission perpendicular to rotation axis? POX 4: Independent HI cloud + strange HI kinematics?
He 2-10: Extended HI emission perpendicular to rotation axis? POX 4: Independent HI cloud + strange HI kinematics?
A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez A multiwavelength analysis of BCDGs – Sydney, June 24, 2009 Ángel R. López-Sánchez
ConclusionsConclusions
Detailed multiwavelength analysis of BCDGs
– Optical / NIR imagery– H imagery– Deep optical spectroscopy
(long slit and echelle)– H I and 20cm observations
H I data are fundamental to understand the dynamical evolution of these objects.
Despite the environment,
ALL studied BCDGs show interactions features, very evident in the majority of them, confirming the main result found in our analysis of a sample of Wolf-Rayet galaxies
(López-Sánchez PhD, 2006; López-Sánchez & Esteban 2008, 2009a,b)
Detailed multiwavelength analysis of BCDGs
– Optical / NIR imagery– H imagery– Deep optical spectroscopy
(long slit and echelle)– H I and 20cm observations
H I data are fundamental to understand the dynamical evolution of these objects.
Despite the environment,
ALL studied BCDGs show interactions features, very evident in the majority of them, confirming the main result found in our analysis of a sample of Wolf-Rayet galaxies
(López-Sánchez PhD, 2006; López-Sánchez & Esteban 2008, 2009a,b)
Are interactions between dwarf objects the main triggering mechanism of starbursts, specially in BCDGs?
Many surprises will come from HI surveys, i.e. using ASKAP, Australia SKA Pathfinder!!
Are interactions between dwarf objects the main triggering mechanism of starbursts, specially in BCDGs?
Many surprises will come from HI surveys, i.e. using ASKAP, Australia SKA Pathfinder!!