External Galaxies

Eduardo BañadosRaffaella CapassoJonathan FreudlichAlina StreblyanskaPaloma Martínez

Ilhuiyolitzin VillicañaYasir EzzuldeenCelia Verdugo

Motivation

- Sample of external galaxies. CO detection

-EMIR E0/E2 CO(1-0) @ 115GHz & CO(2-1) @230 GHz

-Determine molecular gas mass from CO emission

Observing strategy

Sources:

M82; SSET 02, 17, 24, 25, 26, 27, 28, 29, 30

High Stellar Masses and Star Formation Rates

Collision of 2 galaxies OTF map

Observation preparation

sources:checking visibility in ASTRO

checking calibrators in XEPHEM

Observations preparationsetup:RECEIVER /CLEAR ! Clean receiverBACKEND /CLEAR ! Clean backends

RECEIVER E090 CO(1-0) 111.4 UI /Hor UI /Ver UI ! Select E0 as receiverRECEIVER E230 CO(2-1) 220.64 UI /Hor UI /Ver UI ! Select E2 as receiver

SWWOBBLER -20 +20 /TPHASE 0.5 ! Switching mode

BACKEND FTS /DEF

Observations results

targets observed: M82, SSET-17 (total: 0.5 hrs)

problems: bad weather, telescope out of order.

Results: Only detection in M82

Observations results

targets observed: M82, SSET-17 (total: 0.5 hrs)problems: bad weather, telescope out of order.Results: Only detection in M82

CO(2-1) cannot be observed at 1mm!(at rms~1K no detection)

CO(1-0) 12 min exp. time~0.2K rms

Fitting process

1 component 2 components

Class command: line 2

Analysis

Fitting results:

M82 (2 components) :

C1= 252.17+/-2.125 K km/s

C2= 155.78+/-1.817 K km/s

Ico = 407.95 K km/s (sum of both components)

30m @115GHz: Feff

=94, Beff=78

θ: 0.37’ CO(1-0) beamsize

λ: 0.26 cm

Then SCO = 2460 Jy km/s

Analysis

Mmol = αCO LCO (Bolatto et al 2013)

LCO

= 2453 SCO

Δv DL2/(1+z) D = 3.7 Mpc → LCO=9+/-0.2 K km s-1 pc2

X

CO=2x1020(K km/s)-1 → α

CO=4.3Msun(K km s-1 pc2)-1 For the MW

Then, MH2= 4.0 x 108Msun

Correcting for He (1.36): Mgas

= 5.4 x 108 Msun

Comparison with literature: Mgas

= 1.3 x 109 Msun

(Walter et al 2002)

Correcting for He (1.36): Mgas

= 5.4 x 108 Msun

Comparison with literature: Mgas

= 1.3 x 109 Msun

(Walter et al 2002)

We are observing just a fraction of the galaxy

Gas Mass

Kiit Peak 2.1mtBlue: BRed: HaGreen: V

LCN = 6.823 x 106 +/- 0.5 x 106 K km s-1 pc2 (CN @ 113.5 GHz)

LCN = 3.016 x 106 +/- 0.9 x 106 K km s-1 pc2 (CN @ 113.19 GHz)

L13CO

= 5.142 x 106 +/- 0.5 x 106 K km s-1 pc2

Other lines

Carilli & Walter 2013

Conclusions

● CO(1-0) (3mm) and other lines detected even in bad weather (pwv ~ 40 mm)

● CO(2-1) (1 mm) needs good weather

● Mgas

calculated in 5 x 108 Msun

(fraction of the total mass)