A VLT/MUSE analysis of HeIIλ1640 emitters at z=2-4

E X P L O R I N G H E I I 1 6 4 0 E M I S S I O N L I N E P R O P E R T I E S AT Z = 2 - 4

@themiyan

T H E M I YA N A N AYA K K A R A

Jarle Brinchmann, Leindert Boogaard, Rychard Bouwens, Sebastiano Cantalupo, Anna Feltre,

E > 5 4.4 e V

Po p I I I

S t ar s

( To p h e av y I M F)

C u r r e n t s t e l l a r p o p u l a t i o n / p h o t o i o n i s a t i o n

m o d e l s f a i l t o p r e d i c t t h e o b s e r v e d H e I I f e a t u r e s

C u r r e n t s t e l l a r p o p u l a t i o n / p h o t o i o n i s a t i o n

m o d e l s f a i l t o p r e d i c t t h e o b s e r v e d H e I I f e a t u r e s

H e + i o n i s i n g p h o t o n s c a n b e p r o d u c e d v i a

m u l t i p l e m e c h a n i s m s , s o s o m e s o l u t i o n s i n c l u d e :

•

Decrease Z/mass threshold to produce W-R stars

•

Include contribution from X-Ray Binaries

•

Increase N of Young massive stars

•

Consider contributions from Shocks and AGN

T e s t i n g t h e s e m o d e l s a n d p r o v i d i n g c o n s t r a i n t s

r e q u i r e s H e I I e m i t t e r s i n a v a r i e t y o f c o n d i t i o n s

P.1

W e u s e m u l t i p l e G T O p o i n t i n g s w i t h d e e p e x p o s u r e s

t o i d e n t i f y a n y H e I I λ

1 6 4 0

e m i t t e r s

W e u s e m u l t i p l e G T O p o i n t i n g s w i t h d e e p e x p o s u r e s

t o i d e n t i f y a n y H e I I λ

1 6 4 0

e m i t t e r s

1.0

0.5

0.0

0.5

4

3

2

1

0

1

2

log

₁₀

(EW (Heii 1640)[˚

A])

3

2

1

0

1

log

10

(EW

(O

iii

]

1666)[

˚ A])

4

3

2

1

0

1

2

log

₁₀

(EW (Heii 1640)[˚

A])

4

3

2

1

0

1

2

log

₁₀

(EW (Heii 1640)[˚

A])

3

2

1

0

1

log

10

(EW

(O

iii

]

1666)[

˚ A])

4

3

2

1

0

1

2

log

₁₀

(EW (Heii 1640)[˚

A])

40.50 40.75 41.00 41.25 41.50 41.75 1 0 1 2 3 4

log

10

([N

i,

obs

/N

i,

pred

]

HeI

I

1640

)

Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 40.50 40.75 41.00 41.25 41.50 41.75

log

₁₀

(L[HeII 1640]

_obs

(erg/s))

40.50 40.75 41.00 41.25 41.50 41.75 1 0 1 2 3 4

log

10

([N

i,

obs

/N

i,

pred

]

HeI

I

1640

)

Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 40.50 40.75 41.00 41.25 41.50 41.75

log

₁₀

(L[HeII 1640]

_obs

(erg/s))

40.50 40.75 41.00 41.25 41.50 41.75 1 0 1 2 3 4

log

10

([N

i,

obs

/N

i,

pred

]

HeI

I

1640

)

Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 Z = 0.010 40.50 40.75 41.00 41.25 41.50 41.75

log

₁₀

(L[HeII 1640]

_obs

(erg/s))

W e l a c k a c o m p r e h e n s i v e u n d e r s t a n d i n g o f s t e l l a r s p e c t r a i n t h e F U V

w h i c h m a y c o n t r i b u t e t o l a c k i n m e c h a n i s m s p r o d u c i n g o f

E

p h o t o n

> 5 4 e V

© S t a n w a y & E l d r i d g e ( 2 0 19 )

T h e l a c k o f h a r d i o n i s i n g p h o t o n s i s

Is it variations in the IMF?

© G r ä f e n e r & V i n k ( 2 0 1 5 ) +

© G r ä f e n e r & V i n k ( 2 0 1 5 ) +

© G r ä f e n e r & V i n k ( 2 0 1 5 ) +

Is it very massive stars at Eddington limit?

© G r ä f e n e r & V i n k ( 2 0 1 5 ) +

Is it very massive stars at Eddington limit?

Is it contributions from X-ray Binaries?

Is it contributions from X-ray Binaries?

© S c h a e r e r + ( 2 0 19 )

Is it contributions from X-ray Binaries?

© S c h a e r e r + ( 2 0 19 )

B PAS S o n ly

How can we provide observational

constraints?

©Bacon et al.,

MUSE XDF program

MUSE HFF program

©Wisotzki et al.

©Wisotzki et al.

MUSE HFF program

2 0 0 h p r o g r a m w i t h 4 H F F p ar al le l f i e l d s .

E a c h f i e l d :

•

D e e p : 1 ` x 1 ` 2 5 h p o i nt i n g

•

M e d i u m : 2 ` x 2 ` 5 h p o i nt i n g s

•

s h al lo w : 3 ` x 3 ` 1.7 h p o i nt i n g s

©Wisotzki et al.

©Wisotzki et al.

C O N C L U S I O N S

•

_{We compose a catalogue with ≈}

13

_{HeII1640 detections from MUSE (and ≈}

20

_{tentative detections from}

other public surveys).

•

Using Gutkin et al.,

(2016)

_{models we show our observed emission line ratios can be reproduced via}

high-U sub-solar Z models.

•

Including effects of binaries from Xiao et al.,

(2018)

_{models makes the model parameters}

degenerate.

•

We show even BPASS models are unable to reproduce the observed HeIIλ1640 and OIII]λ1666 equivalent

widths.

•

We show that matching HeIIλ1640 luminosities with BPASS models require ~

1/200

Z

_☉

_{models which}

are in tension with gas phase metallicities inferred via line-ratio diagnostics.

•

IMFs with larger fractions of high mass stars (top heavy) or exotic stellar population mechanisms

such as XRBs or very massive WNh stars that can produce photons at wavelength < 275 Å with

relatively low wind effects are required to match our observed data with models.