Brown Dwarfs in the Era of WISE. Michael Cushing University of Toledo

Transcription

1 Brown Dwarfs in the Era of WISE Michael Cushing University of Toledo WISE at Feb-10

2 Brown dwarfs were baked into WISE From the 1998 proposal for the Next Generation Sky Survey (NGSS): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

3 Brown dwarfs were baked into WISE From the 1998 proposal for the Next Generation Sky Survey (NGSS): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

4 Brown dwarfs were baked into WISE From the 1998 proposal for the Next Generation Sky Survey (NGSS): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

5 Not on the docket Daniella Bardalez Gagliuffi J-W2 colors and their utility on finding spectral binaries Chris Gelino Uncovering Faint Companions of WISE Brown Dwarfs

6 W1 & W2 were tuned to find cool brown dwarfs 12 H 2 O H 2 O CO T eff = 3500 K H 2 O 2400 K K 1000 K Normalized fν + Constant TiO FeH K H 2 O CH CH 4 4 CH K 2 CH 4 CH 4 CH 4 CIA H 2 NH 3 0 NH 3? NH 3? NH 3? Wavelength (µm)

7 W1 & W2 were tuned to find cool brown dwarfs W1 W2 W3 12 H 2 O H 2 O CO T eff = 3500 K H 2 O 2400 K K 1000 K Normalized fν + Constant TiO FeH K H 2 O CH CH 4 4 CH K 2 CH 4 CH 4 CH 4 CIA H 2 NH 3 0 NH 3? NH 3? NH 3? Wavelength (µm)

8 How do we search for cold brown dwarfs? Cool brown dwarfs are red in W1-W2 We can exploit a unique No. 6, 2010spectral feature THE WIDE-FIELD INFRARE W1-W2 (mag) Wright et al. (2010) 3-color images:d. blue (W1), green (W2), red (W3) courtesy Kirkpatrick Caltech Astronomy Colloquium, April 2014 W2-W3 (mag) Wright etshowing al. (2011, AJ, of 140, 1868) Figure 12. Color color diagram the locations interesting classes of 10 objects. Stars and early-type galaxies have colors near zero, while brown dwarfs are very red in W1 W2, spiral galaxies are red in W2 W3, and ULIRGS tend to be red in both colors.

9 Brown dwarf demographics and cartography

10 WISE has vastly increased the number of late-type brown dwarfs Number T eff (K) L0 L5 T0 T5 Y0 Spectral Type Total=1806 pre WISE=1244 WISE= 299 Y2 DwarfArchives.org (updated)

11 WISE has vastly increased the number of late-type brown dwarfs 1.0 T eff (K) Fraction of Total Discovered not WISE WISE 0.0 L0 L5 T0 T5 Y0 Spectral Type Y2 DwarfArchives.org (updated)

12 WISE has vastly increased the number of late-type brown dwarfs 1.0 T eff (K) Poster: Mike Liu Fraction of Total Discovered 0.8 Surveying the Extended Solar Neighborhood with not WISE Pan- STARRS and WISE WISE 0.0 L0 L5 T0 T5 Y0 Spectral Type Y2

13 WISE is filling out the local 8 pc volume data from Kirkpatrick et al. (2012, ApJ, 753, 156) courtesy Adam Schneider

14 WISE is filling out the local 8 pc volume data from Kirkpatrick et al. (2012, ApJ, 753, 156) courtesy Adam Schneider

15 WISE is filling out the local 8 pc volume Requires parallaxes Dupuy et al. (2013, Sci, 341, 1492) Marsch et al. (2013, ApJ, 762, 119) Tinney et al. (2014, ApJ, 796, 39) Kirkpatrick et al. (Spitzer Cycle 9) Dupuy et al. (Spitzer Cycle 11) data from Kirkpatrick et al. (2012, ApJ, 753, 156) courtesy Adam Schneider

16 WISE is filling out the local 8 pc volume Requires parallaxes Dupuy et al. (2013, Sci, 341, 1492) Marsch et al. (2013, ApJ, 762, 119) Tinney et al. (2014, ApJ, 796, 39) Kirkpatrick et al. (Spitzer Cycle 9) Dupuy et al. (Spitzer Cycle 11) data from Kirkpatrick et al. (2012, ApJ, 753, 156) courtesy Adam Schneider

17 Luhman s binary and brown dwarf

18 Luhman s binary and star Today, 1:30 pm: Kevin Luhman Searching for Brown Dwarfs Near the Sun with WISE Proper Motions

19 WISE W1-W2 > 4.08 J-H = 0.7 J = 23.5 mag d = pc

20 WISE is not a T dwarf 2.0 UGPS 0722 (T9) 1.5 CH 4 CH4 WISE 1828 Normalized f H 2 O H 2 O CH Wavelength (µm) Cushing et al. (2011, ApJ, 743, 50) Cushing et al. (in prep)

21 WISE is not a T dwarf f (1.25 µm) f (1.6 µm), J [4.5] 9! T e < 300 K 2.0 UGPS 0722 (T9) 1.5 CH 4 CH4 WISE 1828 Normalized f H 2 O H 2 O CH Wavelength (µm) Cushing et al. (2011, ApJ, 743, 50) Cushing et al. (in prep)

22 There are ~23 Y dwarfs known Spectroscopic Photometric 6 7 Cushing et al. (2011, ApJ, ) Kirkpatrick et al. (2012, ApJ, 753, 156) 4.5 µ m B WD 0806B Luhman et al. (2011, ApJ, 730, L9) 1 Liu et al. (2012, ApJ, 758, 57) Spitzer/IRAC J ~ 25 mag 1 Tinney et al. (2012, ApJ, 759, 60) 1 Kirkpatrick et al. (2013, ApJ, 776, 128) Spitzer ( ) [ 4.5] (4.5 µm) WISE Cushing et al. (2014, ApJ, 147, 113) Luhman et al. (2014, ApJ, 786, L18) 1 Pinfield et al. (2014, MNRAS, 444, 1931) Spitzer/IRAC J > 24 mag 3 Schneider et al. (submitted)

23 The Y dwarf sequence 6 Y J H 5 T8 The J-band narrows 4 T9 Normalized f λ 3 2 Y0 Y1 The Y/J/H peaks move towards unity ratios. 1 Y2 The peak of the Y band shifts blueward Wavelength (µm) Schneider et al. (submitted) Cushing et al. (in prep)

24 Brown dwarf astrophysics enabled by WISE

25 Y dwarfs are cool, T eff < 500 K Leggett et al. (2014, ApJ, 799, 37)

26 Y dwarfs are cool, T eff < 500 K Leggett et al. (2014, ApJ, 799, 37)

27 Colors transition at the T/Y boundary Schneider et al. (submitted) see also Liu et al. (2012, ApJ, 758, 57) Lodieu et al. (2013, A&A, 550, L2) Schneider et al. (submitted) see also Mace et al. (2013, ApS, 205, 6) Leggett et al. (2013, ApJ, 763, 130)

28 As a result of Na 2 S and KCl formation increased opacity in the NIR Loss of the 7600 Å K I doublet

29 The mass function summarizes how molecular clouds turn gas into stars Log (dn/dlogm) + Constant dn dm / M =? <latexit sha1_base64="8dgdbqq/4xeha8bnmyjz3f6i2ko=">aaab+xicbvbns8naen34wetxqkcvi0xwvbir9siwvxisygyhcwwz3brln5uwo1fl7e/x4khfq//em//gbzudtj4yelw <latexit sha1_base64="yphaipyey7vhvgymexdhhporcxk=">aaab+xicbvbns8naen3ur1q/uj16wsycf0nsrd0wvxisygyhcwwy3brld5owu1fk7u/x4khfq//em//gbzudtj4yelw3w8y8konmadf9tkorq2vrg+xnytb2zu6exd2/v2kucfvjylpzjkbrzhlqa6y5bwesgog4buxd66nfeqbssts506omhgl6cyszaw2krl0nggcdwifianunnlpv2jxxcwfay8qrsa0vahbtr6cxklzqrbmosnu =2.35 <latexit sha1_base64="ltaigs0u8pfgwtwpp9yzrdt5bn4=">aaab8nicbvbns8naen34wetx1aoxxsj4kkn9vahflx4rgftoqplsn+3szwbz3qgl9g948adi1v/jzx/jts1bwx8mpn6bywzejdntxnw/naxlldw19djgexnre2e3srf/qnnmeeqtlkeqhygmnanqg2y4butfiyk4buxd24nfe M min =? <latexit sha1_base64="hlo/orsh5enmzsnfhnekqhcdt/e=">aaab/3icbvbns8naen34wetx1imhl4tf8frsefuifr14esoyw2hd2gw37dlnjuxoxbjy8a948adi1b/hzx/jts1bwx8mvh1vhp15qsk4bsf5tubmfxaxlksr5dw19y1ne2v7xseposylsyhvkycacs6zcxweaywkksgqrbkmrkz+84epzwn5b8oeerhpsr5y Stellar Mass (M )

30 The mass function is most sensitive to the coolest brown dwarfs Number per 100 K within 10 pc M min =1 M Jup α= 1 α=0 (also M min =10 M Jup ) α=+1 dn dm / M T eff (K)

31 We can rule out α= α=+1.0 Number per 100 K within 10 pc 10 1 WISE α=0.0 α= M Jup 5 M Jup And, a simple power law doesn t appear to match the data well T eff (K) Kirkpatrick et al. (2012, ApJ, 753, 156)

32 We can rule out α= α=+1.0 Number per 100 K within 10 pc 10 1 Poster: Mariusz Gromadzki α=0.0 WISE α= M Jup 5 M Jup And, a simple power law doesn t appear to match the data well. Searching for Y dwarfs at the faint limits of WISE T eff (K) Kirkpatrick et al. (2012, ApJ, 753, 156)

33 Brown dwarfs were baked into WISE From the 1998 proposal for NGSS (Next Generation Sky Survey): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

34 Kinematic searches with WISE Today, 1:30 pm: Kevin Luhman Searching for Brown Dwarfs Near the Sun with WISE Proper Motions Today, 4:35 pm: Adam Schneider The NEOWISE-Reactivation Proper Motion Survey - Methods and Initial Result Thursday, 4:20 pm: Kendra Kellogg Searching for Ultracool Subdwarfs Using the AllWISE Motion Survey

35 Brown dwarfs were baked into WISE From the 1998 proposal for NGSS (Next Generation Sky Survey): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

36 Brown dwarfs were baked into WISE From the 1998 proposal for NGSS (Next Generation Sky Survey): The primary scientific objectives of NGSS are: The nature and evolutionary history of ultra-luminous infrared galaxies (ULIRGs), and the identification of the single most luminous galaxy in the universe ( A.1.2.4). The space density, mass function, and formation history of brown dwarf stars in the solar neighborhood. NGSS will be exceptionally sensitive to old, cold brown dwarf stars with T ~ K (Jupiter-Gliese 229B), among which is likely to be the nearest star to the sun ( A.1.2.5).

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