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Strong Declining UV Emission From A Newborn Type Ia Supernova Yi Cao (Caltech)

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  • Strong Declining UV Emission From A Newborn Type Ia Supernova

    Yi Cao (Caltech)

  • 2

  • 3

  • 4

  • 5

    (Courtesy of M. Sullivan)

  • 6

    (Courtesy of M. Sullivan)

  • 7

    UV Observations of SNe Ia

    Days Since Explosion

    Abs

    olute

    Mag

    nitu

    de

    Abs

    olute

    Mag

    nitu

    de

    (Milne et al. 2010; Brown et al. 2012a, 2012b)

  • 8

    (Courtesy of D. Kasen)

  • 9

    (Kasen 2010)

    X-ray UV

  • 10

    Fast & Furious

    [06:04] 1st obs.

    [06:55] 2nd cand[06:45] 2nd obs.

    [06:12] 1st cand [07:05] cand saved [09:04] Gemini-N obs.

    [12:43] Gemini-N spec. reduced

    [01:25] Swift obs.

    April 2, 2015 April 3, 2015

  • 11

    iPTF14atg: Discovery

    redshift: 0.021

    (Cao et al. 2015 Nature)

  • 12

    iPTF14atg: Swift Lightcurve

    (Cao et al. 2015 Nature)

    11121314151617

    uvw2 u

    14151617181920

    91011121314151617

    uvm2 b

    14151617181920

    0 2 4 6 8 10 12 14 16 18

    11121314151617

    uvw1

    0 2 4 6 8 10 12 14 16 18

    v

    14151617181920

    DDys since explosion

    Abs

    olut

    e 0

    Dgni

    tude

    Abs

    olut

    e 0

    Dgni

    tude

    UV Luminosity: 3e41 erg/sDays Since Explosion

    Abs

    olute

    Mag

    nitu

    de

    Abs

    olute

    Mag

    nitu

    de

  • 13

    iPTF14atg: Swift Lightcurve

    (Cao et al. 2015 Nature)

    11121314151617

    uvw2 u

    14151617181920

    91011121314151617

    uvm2 b

    14151617181920

    0 2 4 6 8 10 12 14 16 18

    11121314151617

    uvw1

    0 2 4 6 8 10 12 14 16 18

    v

    14151617181920

    DDys since explosion

    Abs

    olut

    e 0

    Dgni

    tude

    Abs

    olut

    e 0

    Dgni

    tude

    Binary separation: 60 or 90 Rsun

  • 14

    1000 2000 3000 4000 5000 6000 7000 8000 9000WDvelengWh ()

    0.0

    0.5

    1.0

    1.5

    2.0

    2.5

    )lux

    Den

    siWy

    (ergs/s/cm

    2/

    )

    1e16

    iPTF14atg: Spectral Energy Distribution

    (Cao et al. 2015 Nature)

    Swift/UVOT

    R-bandOptical Spec.

    60 Rsun90 Rsun

    Rest-Frame Wavelength

    Flux

    Den

    sity F

    _lam

    bda

  • 15

    (Cao et al. 2015 Nature)

    iPTF14atg: Optical Lightcurver-B

    and A

    bsolu

    te M

    agni

    tude

    Days Since Peak

  • 16

    iPTF14atg: Optical Spectra

    4000 5000 6000 7000 8000 90005esW-)rame WaveOenJWh ()

    6Fa

    Oed

    )Oux

    + 2

    IIseW

    0ay 6.96

    0ay 15.96

    0ay 24.46

    -une 3.15

    6i II C II 2 I6 II7i IICa II Ca II0J II

    )e II/III

    612002es@max

    612002es@+1 weeN

    4000 5000 6000 7000 8000 90002bserver-)rame WaveOenJWh ()

    Rest-Frame Wavelength

    Black: iPTF14atgGreen: SN2002es

    During UV flare

    About 10 days before maxAround maxAbout a week after max

    (Cao et al. 2015 Nature)

  • 17

    3000 4000 5000 6000 7000 8000 9000 10000

    2bserved WaveOengWh ()

    0

    1

    2

    3

    4

    5

    6

    7

    8

    F(ergss1cm

    1)

    1e11

    iPTF14atg: Host GalaxyStellar Mass: a few times 1e10 Msun

    No Star Formation

    Observed Wavelength

  • 18

    (Olling et al. 2015 Nature)

  • 19

    Conclusion

    An strong UV flare is seen in a Type Ia SN iPTF14atg.

    The UV flare is consistent with the SN-companion interaction signature.

    The observations of iPTF14atg together with other recent observations strongly suggest that SNe Ia have multiple origins.

    Future UV observations will help determine the fraction of SNe Ia originating from the single-degenerate channel.