Display data from paper

Select data type:

MOS11 - Methanol and water masers in IRAS 20126+4104: the distance, the disk, and the jet

Short title: Moscadelli et al. (2011)
Authors: Moscadelli, L.Cesaroni, R.Rioja, M. J.Dodson, R.Reid, M. J.
Journal: Astronomy and Astrophysics, Volume 526, id.A66, 9 pp.
Bibcode:

Target type: High_mass_SFR
Transitions: H2O_22

Abstract
Context. Knowledge of the distance to high-mass star forming regions is crucial to obtain accurate luminosity and mass estimates of young OB-type (proto)stars and thus better constrain their nature and age. IRAS 20126+4104 is a special case, being the best candidate of a high-mass (proto)star surrounded by an accretion disk. Such a fact may be used to set constraints on theories of high-mass star formation, but requires confirmation that the mass and luminosity of IRAS 20126+4104 are indeed typical of a B0.5 star, which in turn requires an accurate estimate of the distance. Aims: The goal of our study is twofold: to determine the distance to IRAS 20126+4104, using the parallax of H₂O masers associated with the source, and unveil the 3D velocity field of the disk, through proper motion measurements of the 6.7 GHz CH₃OH masers. At the same time, we can also obtain an estimate of the systemic velocity in the plane of the sky of the disk+star system. Methods: We used the Very Long Baseline Array and the European VLBI Network to observe the 22.2 GHz H₂O and 6.7 GHz CH₃OH masers in IRAS 20126+4104 at a number of epochs suitably distributed in time. The absolute positions of the maser features were established with respect to reference quasars, which allowed us to derive absolute proper motions. Results: From the parallax of the H₂O masers we obtain a distance of 1.64 Â� 0.05 kpc, which is very similar to the value adopted so far in the literature (1.7 kpc) and confirms that IRAS 20126+4104 is a high-mass (proto)star. From the CH₃OH masers we derive the component in the plane of the sky of the systemic velocity of the disk+star system (-16 km s^-1 in right-ascension and +7.6 km s^-1 in declination). Accurate knowledge of the distance and systemic velocity allows us to improve on the model fit to the H₂O maser jet presented in a previous study. Finally, we identify two groups of CH₃OH maser features, one undergoing rotation in the disk and possibly distributed along a narrow ring centered on the star, the other characterised by relative proper motions indicating that the features are moving away from the disk, perpendicular to it. We speculate that the latter group might be tracing the disk material marginally entrained by the jet. Conclusions: VLBI multi-epoch observations with phase referencing are confirmed to be an excellent tool for distance determinations and for the investigation of the structure and 3D velocity field within a few 100 AU from newly born high-mass stars. Based on observations carried out with the NRAO Very Large Baseline Array and European VLBI Network.

Abstract

Context. Knowledge of the distance to high-mass star forming regions is crucial to obtain accurate luminosity and mass estimates of young OB-type (proto)stars and thus better constrain their nature and age. IRAS 20126+4104 is a special case, being the best candidate of a high-mass (proto)star surrounded by an accretion disk. Such a fact may be used to set constraints on theories of high-mass star formation, but requires confirmation that the mass and luminosity of IRAS 20126+4104 are indeed typical of a B0.5 star, which in turn requires an accurate estimate of the distance.
Aims: The goal of our study is twofold: to determine the distance to IRAS 20126+4104, using the parallax of H₂O masers associated with the source, and unveil the 3D velocity field of the disk, through proper motion measurements of the 6.7 GHz CH₃OH masers. At the same time, we can also obtain an estimate of the systemic velocity in the plane of the sky of the disk+star system.
Methods: We used the Very Long Baseline Array and the European VLBI Network to observe the 22.2 GHz H₂O and 6.7 GHz CH₃OH masers in IRAS 20126+4104 at a number of epochs suitably distributed in time. The absolute positions of the maser features were established with respect to reference quasars, which allowed us to derive absolute proper motions.
Results: From the parallax of the H₂O masers we obtain a distance of 1.64 Â� 0.05 kpc, which is very similar to the value adopted so far in the literature (1.7 kpc) and confirms that IRAS 20126+4104 is a high-mass (proto)star. From the CH₃OH masers we derive the component in the plane of the sky of the systemic velocity of the disk+star system (-16 km s^-1 in right-ascension and +7.6 km s^-1 in declination). Accurate knowledge of the distance and systemic velocity allows us to improve on the model fit to the H₂O maser jet presented in a previous study. Finally, we identify two groups of CH₃OH maser features, one undergoing rotation in the disk and possibly distributed along a narrow ring centered on the star, the other characterised by relative proper motions indicating that the features are moving away from the disk, perpendicular to it. We speculate that the latter group might be tracing the disk material marginally entrained by the jet.
Conclusions: VLBI multi-epoch observations with phase referencing are confirmed to be an excellent tool for distance determinations and for the investigation of the structure and 3D velocity field within a few 100 AU from newly born high-mass stars.

Based on observations carried out with the NRAO Very Large Baseline Array and European VLBI Network.

Download as: Table (CSV)
View as list of objects

Detection table from Moscadelli et al. (2011)

Export table to csv

Hide / Show individual components

ID	Obs. RA	Obs. Dec	l	b	Group id	Source name	Image	Descr.	Line	V_peak	Telescope	Detection	Class	Dist. (parallax)	Date
	(J2000)	(J2000)	(deg.)	(deg.)					H₂O	(km/s)		Yes/No		(kpc)
1	+20 14 26.0253	+41 13 32.666	78.1223	3.6329	G78.122+3.633	IRAS 20126+4104	Image	Descr	22 GHz;	-5.3	VLBA	+H₂O +CH₃OH I +CH₃OH II +OH	SFR	1.64 (0.05)	Jan 2008 - Jan 2009

DSS colored	2MASS colored	WISE colored
SDSS color	IRAC color I1,I2,I4	GLIMPSE 360
PACS color (70-160 um)	SPIRE color (250-500 um)	NVSS (1.4GHz)
ATLASGAL 870 um	ATLASGAL 870 um + Planck	Bolocam 1.1 mm
UKIDSS K Download UKIDSS K FITS	2MASS K Download 2MASS K FITS

select MAX(h2o_data_all.ra_hms) as ra_hms,MAX(h2o_data_all.dec_dms) as dec_dms,MAX(h2o_data_all.source_name) as source_name,MAX(h2o_data_all.ra) as ra,MAX(h2o_data_all.dec) as dec,MAX(h2o_data_all.l) as l,MAX(h2o_data_all.b) as b,MAX(h2o_data_all.grp) as grp,MAX(h2o_data_all.other_name) as other_name,MAX(h2o_data_all.other_desc) as other_desc,BOOL_OR(thermal) as thermal,MAX(h2o_data_all.line) as line,MAX(h2o_data_all.vrange) as vrange,MAX(h2o_data_all.vpeak) as vpeak,MAX(h2o_data_all.peak) as peak,MAX(h2o_data_all.fwhm) as fwhm,MAX(h2o_data_all.int) as int,MAX(h2o_data_all.rms) as rms,MAX(h2o_data_all.units) as units,MAX(h2o_data_all.units_rms) as units_rms,MAX(h2o_data_all.date_txt) as date_txt,MAX(h2o_data_all.telescope_ref) as telescope_ref,MAX(h2o_data_all.telescope_conf) as telescope_conf,MAX(h2o_data_all.v_step) as v_step,MAX(h2o_data_all.beam) as beam,MAX(h2o_data_all.beam_maj) as beam_maj,MAX(h2o_data_all.beam_min) as beam_min,MAX(h2o_data_all.beam_pa) as beam_pa,MAX(h2o_data_all.ref) as ref,MAX(h2o_data_all.list_ref) as list_ref,MAX(h2o_data_all.ascii) as ascii,MAX(h2o_data_all.url) as url,MAX(h2o_data_all.image) as image,MAX(h2o_data_all.image2) as image2,MAX(h2o_data_all.image3) as image3,MAX(h2o_data_all.descr) as descr,MAX(h2o_data_all.id) as id,BOOL_OR(mjy_flag) as mjy_flag,BOOL_OR(rms_mjy_flag) as rms_mjy_flag,MAX(h2o_data_all.dist) as dist,1 as dist_parallax,MAX(h2o_data_all.date_txt) as date_txt,MAX(line_det) as line_det,MAX(type) as type,MAX(simbad_types_cat) as simbad_types_cat FROM h2o_data_all  LEFT JOIN all_objects_withmet ON h2o_data_all.grp=all_objects_withmet.group_name LEFT JOIN object_categories ON all_objects_withmet.group_name = object_categories.group_name_cat AND object_categories.tbl_cat = 'all_objects_withmet' LEFT JOIN transitions ON h2o_data_all.line=transitions."Line"  WHERE ref ilike 'MOS11' AND detected=true AND hide=false GROUP BY ref

select h2o_data_all.ra_hms,h2o_data_all.dec_dms,h2o_data_all.source_name,h2o_data_all.ra,h2o_data_all.dec,h2o_data_all.l,h2o_data_all.b,h2o_data_all.grp,h2o_data_all.other_name,h2o_data_all.other_desc,h2o_data_all.thermal,h2o_data_all.line,h2o_data_all.vrange,h2o_data_all.vpeak,h2o_data_all.peak,h2o_data_all.fwhm,h2o_data_all.int,h2o_data_all.rms,h2o_data_all.units,h2o_data_all.units_rms,h2o_data_all.date_txt,h2o_data_all.telescope_ref,h2o_data_all.telescope_conf,h2o_data_all.v_step,h2o_data_all.beam,h2o_data_all.beam_maj,h2o_data_all.beam_min,h2o_data_all.beam_pa,h2o_data_all.ref,h2o_data_all.list_ref,h2o_data_all.ascii,h2o_data_all.url,h2o_data_all.image,h2o_data_all.image2,h2o_data_all.image3,h2o_data_all.descr,h2o_data_all.id,h2o_data_all.mjy_flag,h2o_data_all.rms_mjy_flag,h2o_data_all.dist,h2o_data_all.dist_parallax,h2o_data_all.date_txt,line_det,type,simbad_types_cat FROM h2o_data_all   LEFT JOIN all_objects_withmet ON h2o_data_all.grp=all_objects_withmet.group_name LEFT JOIN object_categories ON all_objects_withmet.group_name = object_categories.group_name_cat AND object_categories.tbl_cat = 'all_objects_withmet' LEFT JOIN transitions ON h2o_data_all.line=transitions."Line"  WHERE ref ilike 'MOS11' AND detected=true AND hide=false ORDER BY detected DESC,id

Display data from paper

MOS11 - Methanol and water masers in IRAS 20126+4104: the distance, the disk, and the jet

View as list of objects

Detection table from Moscadelli et al. (2011)