JEDI meeting OA Capodimonte, April 9 th -10 th 2015 Simone Antoniucci INAF – Osservatorio Astronomico di Roma Elisabetta Rigliaco, Juan Alcalà, Brunella Nisini, Antonella Natta, Teresa Giannini, Beate Stelzer HI lines in Lupus PMS Objects An X-Shooter View HI lines in Lupus PMS Objects An X-Shooter View “Let us make computations of the stars”

Tracing circumstellar gas in YSOs: HI lines OAC, Apr S. Antoniucci - HI lines2 Winds/jet Accretion shock Accretion flows adapted from Dullemond & Monnier 2010 Optical/near IR HI lines trace high density gas in inner circumstellar structures. HI lines commonly used as: 1) proxy for accretion luminosity (HI directly or indirectly trace the accretion process) 2) probe of gas properties (temperature, density, and kinematics), HI profiles do not provide clear answer about line origin) Emission region is very compact (< 1-10AU) No clear origin: accretion flows, winds?

X-Shooter: the Lupus GTO sample (Alcalà+ 2014) OAC, Apr S. Antoniucci - HI lines3 Lupus sample of 36 T Tauri objects with low-extinction, 0.05 < M  < 1 M  X-Shooter: UV-NIR ( μm) simultaneous spectral coverage, moderate spectral resolution (R~ ) spectra X-Shooter spectra  very good characterization of the sources from spectral features (L , T eff, M , A V ) X-Shooter spectra  direct observation of the blue/UV excess (Balmer jump and continuum) related to accretion shock  model emission  derive accretion parameters (L acc, M acc, veiling) Alcalà

X-Shooter YSO spectra OAC, Apr S. Antoniucci - HI lines4 Sz 72 VIS arm UVB arm NIR arm HβHβ HH H series Pa series Paβ Brγ Br series UV-NIR ( μm) simultaneous spectral coverage, moderate resolution (R~ )  perfect to observe HI lines from Balmer, Paschen, and Brackett series

Recipe for HI lines analysis OAC, Apr S. Antoniucci - HI lines5 Lines of the same series ProfilesFlux ratios Source properties (L , T eff, M acc, …) Models  derive gas properties (case B, local line excitation models,...) Lines from different series X-Shooter: HI lines from Balmer, Paschen, and Brackett series  use info from all detected HI lines! Decrements Paβ HβHβ Paγ/Hβ Hβ-H11

Balmer decrement relative to Hβ Pa decrements relative to Paβ Very good SNR in UVB-VIS arms ensures optimal analysis of the Balmer lines SNR of HI lines in NIR arm is lower  limited information from Paschen and Brackett lines (fair quality only for bright line objects) OAC, Apr S. Antoniucci - HI lines HI decrements in Lupus objects H decrements relative to Hβ  focus on Balmer series Decrement: flux ratios of lines of a series relative to one line used as reference

Type 1Type 2Type 3Type 4 # 3/36# 21/36# 6/36 Balmer decrement shapes Observational study: can the shape be related to different source properties and/or accretion regimes? Is there a link with source profiles? Do models reproduce observed decrements? OAC, Apr S. Antoniucci - HI lines Shape varies with continuity, but we can empirically identify 4 main shape classes Shape  source and gas properties ? “curved”“bumpy”“straight”“L”

Balmer decrements vs source properties OAC, Apr S. Antoniucci - HI lines Correlations between decrement shape and (L , T eff ) Type 1 decrements all associated with sub-luminous sources (objects viewed edge-on  obscuration of inner central region) Type 2 decrements observed at any combination of L , T eff Lower luminosity objects associated with type 2 decrements Type 1 Type 3 Type 2 Type 4 Alcalà

Balmer decrements vs source properties OAC, Apr S. Antoniucci - HI lines No tight correlations with any of the central source properties, but shape tends to be similar in sources with higher accretion rates (type 4 – type 2) Type 1 Type 3 Type 2 Type 4

HI line profile variety OAC, Apr S. Antoniucci - HI lines HβHβ HγHγ HδHδ HεHε H8H8 H9H9 H10 H11 HH narrow symmetric #12/36wide symmetric # 7/36double/triple peaked #17/36 Upper lines of the series become more and more symmetric Narrow symmetric lines slightly (few km/s) blueshifted; blue/red wings extended from ~100 up to ~ km/s

Log M acc Reipurth+ 1996, Folha & Emerson 2002 OAC, Apr S. Antoniucci - HI lines Lower mass accretion rates associated with narrow symmetric profiles 19/36 sources are symmetric Number of sources with blueshifted (8) and redshifted (9) absoptions is comparable narrowwide I HI line profiles

HI line profiles and decrements OAC, Apr S. Antoniucci - HI lines Largest FHWMs in three type 4 sources In most sources FWZI far from what is expected for a Gaussian, up to 1500 Km/s  different emission components (accretion + winds)? In narrow symmetric line sources FWHM is constant within the series, decrement is type 2 FWHM (Hβ vs H9)FWHM vs FWZI in Hβ Gaussian Type 1 Type 3 Type 2 Type 4 Type 1 Type 3 Type 2 Type 4

Decrements, profiles, and opacity OAC, Apr S. Antoniucci - HI lines Narrow symmetric line sources (NS) are compatible with optically thin emission Most type 3 decrements are compatible with optically thin emission All type 1 and 4 decrements are not compatible with optically thin emission Ratios of lines with same upper level for optically thin emission depends only on Einstein coefficients  Pa5/H5 ratio Expected value for optically thin emission Profile types Type 1 Type 3 Type 2 Type 4 Dec types

Comparison with models: case B OAC, Apr S. Antoniucci - HI lines14 Decrements often compared in the past with case B emission (e.g. Hummer & Storey 1987): recombination model in which Ly lines are optically thick, other series optically thin nene Tnene T Type 2Type 3 Most decrements shapes (even type 3!) compatible with case B gas electron densities from 10 7 cm -3 (type 1) up to cm -3 (type 2, type 3), with temperatures as low as K (Bary+ 2008) Problem  consistent with case B assumptions? (lines must remain optically thin! requires strong ionization rates) Very low temperatures are not in agreement with standard accretion models (T~10000 K)

Comparison with models: Kwan’s models OAC, Apr S. Antoniucci - HI lines15 Type 4 shapes (strong accretors) are reproduced well with gas densities of order cm -3, temperatures K  in agreement with standard accretion models Some degeneracy for parameters determination Type 3 not reproduced Limit is “single value” conditions  what if emission is made of different gas components? Collaboration with John Kwan to modify models based on input from our observations  paper II Type 2 Kwan & Fischer 2011 models: “local line excitation calculations”. Self-consistent radiative transfer calculations, assuming one density, one temperature, a velocity gradient, and ionization rate for the gas (local conditions)  can manage optically thick emission Type 4

Conclusions: type 1 decrements OAC, Apr S. Antoniucci - HI lines16 HβHβ HγHγ HδHδ HεHε H8H8 H9H9 H10 H11 All associated with subluminous sources (viewed edge-on  strong obscuration of the central inner region, described in terms of grey extinction) Decrement shape possibly due to 1) residual extinction that is not accounted for; 2) emission mostly coming from outer lower density regions (decrement shape is compatible with case B) v (km/s) Normalized Flux

Relative Flux Conclusions: type 2 decrements OAC, Apr S. Antoniucci - HI lines Type 2 is the most common shape (58% of sample) Narrow symmetric profile (33% of sample)  type 2 decrement, optically thin emission, low M acc Type 2 decrements also observed in sources with more complex profiles, not always optically thin Using Kwan models  densities ~ cm -3, temperatures ~ K Narrow symmetric lines (and type 2) may be “base”, standard HI emission in YSOs (magnetospheric origin?) HβHβ HγHγ HδHδ HεHε H8H8 H9H9 H10 H11 v (km/s) Normalized Flux

Conclusions: type 4 decrements OAC, Apr S. Antoniucci - HI lines18 Relative Flux Often associated with strong accretors, emission is optically thick Profiles are typically very wide (accretion – line width relation)  wind component? Shape not compatible with case B predictions but well reproduced by Kwan models, which indicate high densities (~10 11 cm -3 ) and temperatures ~10000 K  in these sources the emission is coming from gas that is well described in terms of a single density and temperature HβHβ HγHγ HδHδ HεHε H8H8 H9H9 H10 H11 Normalized Flux v (km/s)

Conclusions: type 3 decrements OAC, Apr S. Antoniucci - HI lines HβHβ HγHγ HδHδ HεHε H8H8 H9H9 H10 H11 Normalized Flux Most difficult to interpret, “differential” line opacity within the series cannot explain the bump Bump is reproduced by case B prediction, but at high densities and low temperatures (consistency issue) Prototype source is subluminous  objects in which inner region is obscured?  bulk of the emission from outer regions Can the bump be reproduced in improved Kwan models?  paper II v (km/s)

Conclusions: HI lines work schedule Paper I (Antoniucci+) Focus on observations: atlas, classifications, observational relationships, comparison with current standard models, main focus on Balmer series  draft almost ready Paper II (Rigliaco+) Focus on comparison with improved models: information from ratios of lines from different series, interaction with John Kwan for improvement of local line excitation models, based on input from our data; derivation of physical properties of the gas OAC, Apr S. Antoniucci - HI lines Expand the sample Is the decrement shape variable?  what is the impact of the geometry?  good case for a new observational programme…

Grazie “A che tante facelle?” – G. Leopardi

OAC, Apr S. Antoniucci - HI lines The strange case of Sz123 A and B ESTINZIONE !!!

OAC, Apr S. Antoniucci - HI lines Balmer decrements in Lupus objects

OAC, Apr S. Antoniucci - HI lines Paschen decrements in Lupus objects

HI decrements in Lupus objects Balmer decrement relative to Hβ (up to H15) Manara+ 2013, Stelzer Class III objects (no accretion, HI from chromosphere) OAC, Apr S. Antoniucci - HI lines

Nisini, Antoniucci Bary HI decrements Decrement: flux ratios of lines of the series relative to one used as reference Use info from all lines to derive properties (density, temperature) of emitting gas Decrements have often been interpreted assuming case B predictions (i.e. Lyman series optically thick, other series optically thin) or blackbody emission Problem! Although shapes can be fit well assuming case B, one gets very high densities ( cm -3 ) and fairly low temperatures ( K), Bary  hardly consistent with case B assumptions (lines must be optically thin!) Sample of 15 T Tauri Stars Lupus OAC, Apr S. Antoniucci - HI lines

Comparison with case B OAC, Apr S. Antoniucci - HI lines27

Decrements vs source properties OAC, Apr S. Antoniucci - HI lines28 No tight correlation with any of the central source properties, but shape is similar in sources with higher accretion rates (type 4 – type 2)

No evident correlations with central source properties Decrements vs source properties

Balmer decrements vs line profiles OAC, Apr S. Antoniucci - HI lines

Balmer decrements vs line profiles OAC, Apr S. Antoniucci - HI lines

1. YSO inner regions 2. POISSON 3. HI lines with Xshooter 4. HI decrements Reipurth 1996, Folha & Emerson 2002 HI decrements vs line profiles

Muzerolle T M acc incl HI line profiles have been modeled in accretion and wind scenarios (e.g. Muzerolle+ 2001)  profile depends not only on M acc, but also on other parameters such as temperature and inclination (geometry!)  look for decrement – profile – source parameters correlations OAC, Apr S. Antoniucci - HI lines