EXOR opti CalInfrared Systematic Monitoring Exorcism at LBT

EXOR opti. Cal-Infrared Systematic Monitoring Exorcism at LBT Simone Antoniucci, Teresa Giannini, D. Lorenzetti, U. Munari, G. Li Causi, B. Nisini, A. Arkharov, V. Larionov, F. Vitali, A. Harutyunyan, A. Di Paola, A. Giunta, F. Strafella, V. Testa INAF OAR, INAF OAPd, INAF IAPS, Univ. of Salento, TNG FGG, Univ. of St. Petersburg, Pulkovo Obs.

Young Stellar Objects T Tauri star ~106 yr Mloss Macc disk [OI] [Fe. II] HI UV exc jet CO Hartmann+ 2016 LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism Dullemond & Monnier 2010 2

Accretion evolution • After main-accretion stars accrete at lower rates (T Tauri phase) • Some T Tauri show powerful intermittent accretion outbursts (FUor/EXor events). • Crucial stage for understanding how accretion halts ( IMF) and how these events affect the protoplanetary disk • Is FUor/EXOr phase an evolutionary stage of all YSOs? Are there outbursts even in the embedded phase? • Assuming short outbursts of enhanced accretion can explain the luminosity problem (accreting YSOs are not as luminous as expected) LBT Users' Meeting 2017 - Firenze Hartmann 1998 S. Antoniucci - EXorcism 3

EXors and FUors Hartmann+ 2016 Kospal+ 2011 V Miller+ 2011 ΔV duration/recurrence Macc FUors 5 -7 mag tens of yrs/? 10 -4 - 10 -5 Msun/yr EXors 3 -4 mag months/several years 10 -5 - 10 -7 Msun/yr LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 4

EXors and FUors Hartmann+ 2016 Kospal+ 2011 V Miller+ 2011 • • Only few EXors known (30), resemble T Tauri stars when quiescent Lack of wide-band spectroscopic information (especially for quiescence) Lack of quantitive comparisons between quiescence and outburst Outburst mechanism not clarified yet: thermal/gravitational instability, triggering from companion? (Audard+ 2014, Vorobyov & Basu 2010) LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 5

EXOR opti. Cal-Infrared Systematic Monitoring EXorcism Photometric monitoring (BVRI, JHK) detect outbursts, monitor color variations (typical sampling 3 -4 weeks) NIR: AZT-24 Campo imperatore, La Silla/REMIR Opt: Asiago 122 cm-telescope, La Silla/ROSS 2 + ancillary smaller facilities Spectroscopic datasets build library of optical-to-near-IR quiescence spectra of known EXors acquisition and monitoring of outburst spectra quiescence-outburst comparison LR: LBT/MODS (optical) , LBT/LUCI (near-IR) (R~1000) HR: Asiago 182 cm-telescope (optical, R~20000); TNG/GIANO (near-IR, R~50000 ) LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 6

Exorcism @LBT • Backup/filler program since 2014 to build an EXor spectral library • MODS (0. 35 -1. 0 μm) + LUCI (1. 0 -2. 4 μm) longslit spectra (R~1000) • Considered sample ~ 30 objects • Library status: complete (optical+near-IR) quiescence spectra of 15 objects, with partial spectra for 5 sources • V 1118 Ori and V 2492 Cyg observed in quiescence and outburst! Giannini+ 2016 V 1184 Tau Giannini+ in prep. V 2492 Cyg LUCI MODS LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 7

Work/Papers LBT spectra enable quantitative analysis of the quiescent phase Macc, fluxes and excitation of accretion/ejection/disk tracers, circumstellar gas parameters, . . . Determination of the “zero level” for the object accretion activity, fundamental for meaningful quantitative comparison with outbursts (constraints on models) Recent Exorcism publications based on LBT data • Antoniucci, Arkharov, Di Paola+ 2014 A&A 565, L 7 (V 1180 Cas characterization) • Antoniucci, Nucita, Giannini+ 2015 A&A 584 A, 21 (V 1180 Cas X-ray vs opt-NIR) • Lorenzetti, Antoniucci, Giannini+ 2015 Ap. J 802, 24 (V 1118 Ori quiescence) • Giannini, Lorenzetti, Harutyunyan+ 2016 a A&A 588 A, 20 (V 1184 Tau variability) • Giannini, Lorenzetti, Antoniucci+ 2016 b Ap. J 819, L 5 (V 1118 Ori outburst – paper I) • Giannini, Antoniucci, Lorenzetti+ 2017 Ap. J 839, 112 (V 1118 Ori outburst – paper II) + … 2 more currently in preparation LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 8

The case of V 1118 Ori • • Giannini+ 2017 LBT Users' Meeting 2017 - Firenze After 10 yr quiescence new major outburst in 2015 -2016 Rapid increase, then stable for a few months (0. 5 mag variations), then slow fading Hint at outburst periodicity? Monitored spectra (MODS+LUCI) S. Antoniucci - EXorcism 9

V 1118 Ori: LBT spectra LUCI MODS quiescence Giannini+ 2016, 2017 LBT Users' Meeting 2017 - Firenze Multiple tracers (accretion/ejection/disk) From quiescence to outburst: • Change of continuum shape (blueing) • Appearance/enhancement of many tracers (HI, He. I, Ca. II, Fe. I, Na. I, CO) S. Antoniucci - EXorcism 10

Mass accretion rate I 2) Macc from fit of UV excess + spectrum (method by Manara+ 2014, 2017; Alcalà+ 2014) determine also star params, extinction Alcalà+ 2014 LBT Users' Meeting 2017 - Firenze Giannini+ 2017 S. Antoniucci - EXorcism 11

Mass accretion rate II 1) Macc from line fluxes via Lacc/Lline relationships (Alcalà+ 14) Lorenzetti+ 2015 quiescence Giannini+ 2017 outburst LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 12

Mass accretion variation Giannini+ 2017 • For the first time evolution of Macc during outburst • <Macc, quiesc> 3. 3 10 -9 Msun/yr <Macc, outb peak> 2. 6 10 -7 Msun/yr • Macc variation by factor ~102 LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 13

Gas properties: HI decrements LBT Users' Meeting 2017 - Firenze • HI Balmer decrements compared with models by Kwan+ 2011 • Outburst temperature in the range ~9000 -15000 K • According to Antoniucci+ 2016 the shape of the Balmer decrements is of type 2 in quiescence and type 4 in outburst; type 4 decrements are typical of high accretors. • Density enhancement by factor of 100, the same as the increase in mass accretion rate S. Antoniucci - EXorcism 14

V 1118 outburst params • Complementary HR spectra from ASIAGO and TNG/GIANO provide info on line profile variations • Comprehensive analysis of the outburst from quiescence to peak: accurate derivation of “Δparams” LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 15

Recap and future Exorcism project • • • Optical/NIR photometric monitoring + spectroscopic characterization of EXors EXor library of spectra 0. 35 -2. 5μm @LBT characterization and determination of “zeroes” for the main parameters (Macc) Fundamental for comparison quiescence vs outburst What’s next @LBT • • Complete the spectral library Exorcism @LSST: LSST will identify lots of EXor candidates (also in younger phases) follow-up with LBT High-resolution observations of inner regions of EXors for investigating triggering mechanism (for instance SHARK!. . . this afternoon) New works: • Giannini+ submitted (V 2492 Cyg outburst) • Antoniucci+ in prep. (Global view, general properties of EXors in quiescence) LBT Users' Meeting 2017 - Firenze S. Antoniucci - EXorcism 16

Thank You A che tante facelle? (G. Leopardi)