The ALMA view of a Carbon Rich AGB Star: The Spectrum of IRC+10216 J. Cernicharo, M. Agúndez, F. Daniel, A. Castro-Carrizo, N. Marcelino, C. Joblin, M. Guélin, J. Goicoechea J. Cernicharo, ICMM, Group of Molecular Astrophysics, jose.cernicharo@csic.es

IRC+10216 observed at all wavelengths with single dishes Brightest mid-IR source in the sky. Nearest C-rich AGB star Sensitive Millimeter Line surveys (rms below a few mK) (2mm = Cernicharo et al., 2000, A&A SS, 142, 181) (3mm = Cernicharo et al., 2014, A&A) (1mm = ongoing) (490-1900 GHz line survey with HIFI; Cernicharo et al., 2010) High spectral resolution Infrared line surveys (TEXES) 14  m region (C2H2, HCN & SiS) Fonfría et al., 2008, ApJ 50% of ISM molecules detected in this source (polar molecules): Metal-bearing : NaCl, KCl, AlCl, AlF, MgNC, MgCN, AlCN, SiNC, SiCN, KCN, NaCN, FeCN,… Carbon chains: CCH, C3H, C4H, C5H, C6H, C7H, C8H, CN, C3N, C5N, HCN, HCCN, HC3N, HC4N, HC5N, HC7N, HC9N Silicon-bearing species: SiO, SiS, SiC, SiC2, SiC3, SiC4 Sulphur-bearing species: CS, CCS, CCCS, C5S Phosphorus-bearing species: PN, CP, HCP, CCP, PH3 Anions: CN-, C3N-, C5N-, C4H-, C6H-, C8H- Nanocosmos Yebes – 06/2/2014

IRC+10216 CO J=2-1 30m Data Extreme Outer Shells Outer carbon radicals Star radius is 0.02”. CO envelope radius >200” IRC+10216 CO J=2-1 30m Data Cernicharo et al. 2014 Extreme Outer Shells Outer carbon radicals Shell (r=14”) Inner Refractory Species. Dust Formation Zone (<1”)

Inner shells Outer shells Very poorly known region Por último, la envoltura circunestelar posee una elevada riqueza de moléculas. En este esquema se representa la estructura de una envoltura circunestelar típica, la cual se extiende desde la superficie de la gigante roja (con temperaturas de 2000-3000 K y densidades de 1e15 cm-3) hasta una distancia de hasta 1 año luz (en donde la temperatura es de unos cuantos grados Kelvin y la densidad es de unas pocas partículas por cm3). En las regiones más cercanas a la fotosfera el gas es denso y caliente y la composición viene en gran medida dada por el equilibrio químico, esto es se forman moléculas estables (CO, H2O, SiO en estrellas ricas en oxigeno y CO, C2H2, y HCN en envoltura ricas en carbono). La composición química puede verse alterada por procesos como ondas de choque asociadas a la pulsación de la estrella (las estrellas AGB son estrellas variables), y a la formación del polvo, la cual ocurre a partir de 5-20 R* cuando la temperatura cae por debajo de unos 1000 K. En la envoltura externa las moléculas comienzan a estar expuestas al campo de radiación UV del ISM y son fotodisociadas, lo que da lugar a una fotoquímica en que los radicales formados intervienen en reacciones químicas rápidas y dan lugar a nuevas especies químicas. Esta química es particularmente rica en envolturas ricas en carbono.

The spectrum of IRC+10216 is rather well known The spectrum of IRC+10216 is rather well known. We are able to identify all isotopologues and vibrationally excited states of abundant species with single dishes and interferometers at 3 and 2 mm and in the line survey with HIFI/Herschel. Line survey at l = 3 mm carried out with the IRAM 30-m radio telescope: - 80.05-115.75 GHz - 1339 emission lines (~37 lines/GHz) - 886 assigned to rotational transitions of 60 molecules (+ different isotopoloques and vibrationally excited states) - 453 unassigned lines (only 31 with TA* > 10 mK) –before anions- - high sensitivity: rms(TA*) < 1 mK for most frequencies Nanocosmos Yebes – 06/2/2014 Rest Frequency (GHz)

LINE SURVEYS Esta figura recoge el conjunto de datos de que disponemos sobre IRC +10216. Consiste en el espectro a longitudes de onda milimétricas (desde 80 a 280 GHz) tal y como ha sido obtenido con el telescopio IRAM 30-m. El espectro consiste en líneas en emisión

 que corresponden a transiciones de rotación de diversas moléculas. Cernicharo et al. 2000 Cernicharo et al. en preparación  que corresponden a transiciones de rotación de diversas moléculas. Como se puede apreciar se ha cubierto prácticamente todo el rango espectral accesible con este telescopio (80-280 GHz). Los receptores actuales operan hasta 360 GHz y seguramente merecería la pena investigar este rango espectral en un futuro próximo. La banda de 1.3 mm es un composite de varias observaciones llevadas a cabo en los últimos 10 años. El barrido espectral a 2 mm se encuentra publicado en Cernicharo et al. 2000. Por su parte, el barrido espectral a 3 mm se encuentra actualmente en preparación para ser publicado y constituye la parte más novedosa.

Cernicharo et al., 2010, A&A, 521, L8

HCN NH3 CN HC3N C3N HC5N HNC CH3CN HC7N HC9N CH2CN HC2N C5N HCCNC C2H3CN C5N- HC4N C3N- HNCCC CO H2O OH H2CO C3O HCO+ C2H2 CH4 C2H C4H C2 C3 C5 l-C3H C6H C5H c-C3H2 CH3C2H c-C3H C2H4 H2C4 C8H C7H H2C6 C6H- C8H- H2C3 C4H- 10-3 10-4 10-5 10-6 10-7 10-8 10-9 10-10 1(-3) 1(-7) 4(-8) 1.3(-8) 2(-9) 7(-10) 8(-5) 3.5(-6) 3(-6) 2.5(-6) 1(-6) 5(-8) 3(-8) 2(-8) 1.4(-8) 8(-9) 3(-9) 1.5(-9) 3(-10) 2(-5) 2(-6) 1.7(-6) 1.4(-6) 4(-7) 2(-7) 7(-9) 6(-9) 4(-9) 2.3(-9) 1.1(-9) 5(-10) CS C2S C3S H2CS H2S C5S 5(-7) 1.2(-8) 1.2(-9) SiC2 SiS SiH4 SiO SiC SiN c-SiC3 SiC4 SiCN SiNC 1.2(-6) 2.2(-7) 1.2(-7) HCP CP PH3 PN C2P 2.5(-8) 1(-8) 1(-9) AlCl NaCN MgNC AlF NaCl AlNC MgCN KCl 3.5(-8) 7.5(-9) 2.5(-10)

ALMA observations in Cycle 0 between 255-275 GHz Four frequency settings with 2 hours of observing time Good UV coverage even with 16 antennas However, serious problems with the data, wrong frequency scale, selfcalibration absolutely necessary to reach the sensitivity goals Cycle 1 observations between 680-700 GHz expected next months Cycle 2 full 3mm line survey also expected soon

The ALMA view of IRC+10216: A forest of U Lines HCN in high energy vibrational levels (>10000 K) SiC2 in v3 and 2v3,… SiS up to v=10 (& isotopologues) SiO up to v=3 HNC in vibrational levels up to 6000 K + hundreds of U lines Cernicharo et al., 2013 ApJ Letters, 778, L25

Plenty of unknown narrow features!!! IRC+10216 as view by ALMA Plenty of unknown narrow features!!! Cernicharo et al., 2013, ApJ, 778, L25 See also Patel et al. 2010, for narrow U-lines at 350 GHz with the SMA Cernicharo et al., 2011, A&A, for narrow lines from HCN v#0

Looking for known species coming ONLY from the dust formation zone. HNC and HCN. Deriving physical conditions Observed (black curves) and modeled (red) line profile of the J =3-2 in vibrationally excited states of HNC as observed with ALMA near ∼270 GHz. The blue and green curves show the corresponding ν2 lines of HCN (blue) and H13CN (green) observed in the same setup, scaled down by factors of 50 and 6 respectively. HNC frequencies (in MHz) and upper level energies (in kelvins) are given at the top of each box (Cernicharo et al., 2013, submitted to ApJ Letters)

Physical parameters HNC abundance profile HNC vibrationally excited traces the region 1-3 R*, i.e., the dust nucleation zone. Mergin HNC and HCN vibrationally excited data will provide a detailed analysis of the 1-20 R* zone.

ALMA from the star to the ISM The physics and the chemistry from the dust formation zone

We have used our own catalogs (MADEX) in addition to CDMS & JPL to try to identify all these U-lines without success. MADEX is very well adapted to the study of the molecular content of IRC+10216 (4950 species with spectroscopic accuracy). No clear identification for all these lines yet. Probably species formed in the dust formation zone, participating in the nucleation of dust seeds and dust growth. Silicon-bearing clusters, carbon-clusters, and metal-bearing species that disappear after a few stellar radii. J=0 l-doubling transitions of the vibrational levels of HCN involving v2. ALMA observations of evolved stars will require a huge effort from the molecular spectroscopy community to characterize the gas composition in the dust formation zone. Even Cycle 0 observations produce spectacular images of the innermost regions of the envelope of CW Leo (IRC+10216). Mass loss history.

Thank you very much for your attention